{ "format_version": 3, "policy": { "external_id": "53dc9e8cb72adc64683dd925b309d5bb", "name": "CIS Ubuntu 24.04 LTS Benchmark v1.0.0 - Level 1 Server", "version": "1.0.2", "description": "Center for Internet Security benchmark — Level 1 server hardening for Ubuntu 24.04 LTS. Generated from CIS_Ubuntu_Linux_24.04_LTS_Benchmark_v1.0.0.pdf.", "author": "Center for Internet Security" }, "tests": [ { "external_id": "067aa014ecacf78804bd818df520cf42", "name": "1.1.1.1 — Ensure cramfs kernel module is not available", "description": "Ensure cramfs kernel module is not available", "rational": "Removing support for unneeded filesystem types reduces the local attack surface of the \nsystem. If this filesystem type is not needed, disable it.", "remediation": "Run the following script to unload and disable the cramfs module: \n- IF - the cramfs kernel module is available in ANY installed kernel: \n\n• Create a file ending in .conf with install cramfs /bin/false in the \n\n/etc/modprobe.d/ directory \n\n• Create a file ending in .conf with blacklist cramfs in the /etc/modprobe.d/ \n\ndirectory \n\n• Run modprobe -r cramfs 2>/dev/null; rmmod cramfs 2>/dev/null to \n\nremove cramfs from the kernel \n\n- IF - the cramfs kernel module is not available on the system...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "lsmod | grep -c '^cramfs ' || true", "selement": "OUTPUT", "condition": "EQUALS", "sinput": "0" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e90668b9b7d104551d63fa5209f57c63", "name": "1.1.1.3 — Ensure hfs kernel module is not available", "description": "Ensure hfs kernel module is not available", "rational": "Removing support for unneeded filesystem types reduces the local attack surface of the \nsystem. If this filesystem type is not needed, disable it.", "remediation": "Run the following script to unload and disable the hfs module: \n- IF - the hfs kernel module is available in ANY installed kernel: \n\n• Create a file ending in .conf with install hfs /bin/false in the \n\n/etc/modprobe.d/ directory \n\n• Create a file ending in .conf with blacklist hfs in the /etc/modprobe.d/ \n\ndirectory \n\n• Run modprobe -r hfs 2>/dev/null; rmmod hfs 2>/dev/null to remove \n\nhfs from the kernel \n\n- IF - the hfs kernel module is not available on the system, or pre-compiled into t...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "lsmod | grep -c '^hfs ' || true", "selement": "OUTPUT", "condition": "EQUALS", "sinput": "0" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "d2e0ab401568d6b9dfe2fa9623bf808b", "name": "1.1.1.4 — Ensure hfsplus kernel module is not available", "description": "Ensure hfsplus kernel module is not available", "rational": "Removing support for unneeded filesystem types reduces the local attack surface of the \nsystem. If this filesystem type is not needed, disable it.", "remediation": "Run the following script to unload and disable the hfsplus module: \n- IF - the hfsplus kernel module is available in ANY installed kernel: \n\n• Create a file ending in .conf with install hfsplus /bin/false in the \n\n/etc/modprobe.d/ directory \n\n• Create a file ending in .conf with blacklist hfsplus in the \n\n/etc/modprobe.d/ directory \n\n• Run modprobe -r hfsplus 2>/dev/null; rmmod hfsplus 2>/dev/null to \n\nremove hfsplus from the kernel \n\n- IF - the hfsplus kernel module is not available on th...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "lsmod | grep -c '^hfsplus ' || true", "selement": "OUTPUT", "condition": "EQUALS", "sinput": "0" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "194520bd2966d4b80911a066141576c2", "name": "1.1.1.5 — Ensure jffs2 kernel module is not available", "description": "Ensure jffs2 kernel module is not available", "rational": "Removing support for unneeded filesystem types reduces the local attack surface of the \nsystem. If this filesystem type is not needed, disable it.", "remediation": "Run the following script to unload and disable the jffs2 module: \n- IF - the jffs2 kernel module is available in ANY installed kernel: \n\n• Create a file ending in .conf with install jffs2 /bin/false in the \n\n/etc/modprobe.d/ directory \n\n• Create a file ending in .conf with blacklist jffs2 in the /etc/modprobe.d/ \n\ndirectory \n\n• Run modprobe -r jffs2 2>/dev/null; rmmod jffs2 2>/dev/null to \n\nremove jffs2 from the kernel \n\n- IF - the jffs2 kernel module is not available on the system, or pre...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "lsmod | grep -c '^jffs2 ' || true", "selement": "OUTPUT", "condition": "EQUALS", "sinput": "0" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6c10de3b9e4c8f9758596e6f1f3ea225", "name": "1.1.1.8 — Ensure udf kernel module is not available", "description": "Ensure udf kernel module is not available", "rational": "Removing support for unneeded filesystem types reduces the local attack surface of the \nsystem. If this filesystem type is not needed, disable it.", "remediation": "Run the following script to unload and disable the udf module: \n- IF - the udf kernel module is available in ANY installed kernel: \n\n• Create a file ending in .conf with install udf /bin/false in the \n\n/etc/modprobe.d/ directory \n\n• Create a file ending in .conf with blacklist udf in the /etc/modprobe.d/ \n\ndirectory \n\n• Run modprobe -r udf 2>/dev/null; rmmod udf 2>/dev/null to remove \n\nudf from the kernel \n\n- IF - the udf kernel module is not available on the system, or pre-compiled into t...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "lsmod | grep -c '^udf ' || true", "selement": "OUTPUT", "condition": "EQUALS", "sinput": "0" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "f1b387f5d96b21b8c302aa490508f67c", "name": "1.1.2.1.1 — Ensure /tmp is a separate partition", "description": "Ensure /tmp is a separate partition", "rational": "Making /tmp its own file system allows an administrator to set additional mount options \nsuch as the noexec option on the mount, making /tmp useless for an attacker to install \nexecutable code. It would also prevent an attacker from establishing a hard link to a \nsystem setuid program and wait for it to be updated. Once the program was updated, \nthe hard link would be broken, and the attacker w...", "remediation": "First ensure that systemd is correctly configured to ensure that /tmp will be mounted at \nboot time. \n\n# systemctl unmask tmp.mount \n\nFor specific configuration requirements of the /tmp mount for your environment, modify \n/etc/fstab. \nExample of using tmpfs with specific mount options: \n\ntmpfs /tmp \n0 \n\ntmpfs defaults,rw,nosuid,nodev,noexec,relatime,size=2G 0 \n\nNote: the size=2G is an example of setting a specific size for tmpfs. \nExample of using a volume or disk with specific mount op...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "tmp.mount", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "80172d506aefb29e43a14450256cc89a", "name": "1.1.2.1.2 — Ensure nodev option set on /tmp partition", "description": "Ensure nodev option set on /tmp partition", "rational": "Since the /tmp filesystem is not intended to support devices, set this option to ensure \nthat users cannot create a block or character special devices in /tmp.", "remediation": "- IF - a separate partition exists for /tmp. \nEdit the /etc/fstab file and add nodev to the fourth field (mounting options) for the \n/tmp partition. \nExample: \n\n /tmp defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /tmp with the configured options: \n\n# mount -o remount /tmp", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /tmp", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nodev" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c18fa0339eacae3d783790d1b941951b", "name": "1.1.2.1.3 — Ensure nosuid option set on /tmp partition", "description": "Ensure nosuid option set on /tmp partition", "rational": "Since the /tmp filesystem is only intended for temporary file storage, set this option to \nensure that users cannot create setuid files in /tmp.", "remediation": "- IF - a separate partition exists for /tmp. \nEdit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the \n/tmp partition. \nExample: \n\n /tmp defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /tmp with the configured options: \n\n# mount -o remount /tmp", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /tmp", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nosuid" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "7c1d5d14fc1dcedd70fb70524ba73d2d", "name": "1.1.2.1.4 — Ensure noexec option set on /tmp partition", "description": "Ensure noexec option set on /tmp partition", "rational": "Since the /tmp filesystem is only intended for temporary file storage, set this option to \nensure that users cannot run executable binaries from /tmp.", "remediation": "- IF - a separate partition exists for /tmp. \nEdit the /etc/fstab file and add noexec to the fourth field (mounting options) for the \n/tmp partition. \nExample: \n\n /tmp defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /tmp with the configured options: \n\n# mount -o remount /tmp", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /tmp", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "noexec" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "30c13e2546fcdfc39ef1f7176e87b49d", "name": "1.1.2.2.1 — Ensure /dev/shm is a separate partition", "description": "Ensure /dev/shm is a separate partition", "rational": "Making /dev/shm its own file system allows an administrator to set additional mount \noptions such as the noexec option on the mount, making /dev/shm useless for an \nattacker to install executable code. It would also prevent an attacker from establishing a \nhard link to a system setuid program and wait for it to be updated. Once the program \nwas updated, the hard link would be broken and the att...", "remediation": "For specific configuration requirements of the /dev/shm mount for your environment, \nmodify /etc/fstab. \nExample: \n\ntmpfs /dev/shm \ndefaults,rw,nosuid,nodev,noexec,relatime,size=2G 0 0 \n\ntmpfs", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /dev/shm", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0e525725b3084ab539a59d87475e8ccb", "name": "1.1.2.3.2 — Ensure nodev option set on /home partition", "description": "Ensure nodev option set on /home partition", "rational": "Since the /home filesystem is not intended to support devices, set this option to ensure \nthat users cannot create a block or character special devices in /home.", "remediation": "- IF - a separate partition exists for /home. \nEdit the /etc/fstab file and add nodev to the fourth field (mounting options) for the \n/home partition. \nExample: \n\n /home defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /home with the configured options: \n\n# mount -o remount /home", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /home", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nodev" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "d59ba2d4fb7c678ef9be4499ddce8bf4", "name": "1.1.2.3.3 — Ensure nosuid option set on /home partition", "description": "Ensure nosuid option set on /home partition", "rational": "Since the /home filesystem is only intended for user file storage, set this option to \nensure that users cannot create setuid files in /home.", "remediation": "- IF - a separate partition exists for /home. \nEdit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the \n/home partition. \nExample: \n\n /home defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /home with the configured options: \n\n# mount -o remount /home", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /home", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nosuid" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "3562d1b7d586dd166225122421ddcac3", "name": "1.1.2.4.2 — Ensure nodev option set on /var partition", "description": "Ensure nodev option set on /var partition", "rational": "Since the /var filesystem is not intended to support devices, set this option to ensure \nthat users cannot create a block or character special devices in /var.", "remediation": "- IF - a separate partition exists for /var. \nEdit the /etc/fstab file and add nodev to the fourth field (mounting options) for the \n/var partition. \nExample: \n\n /var defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /var with the configured options: \n\n# mount -o remount /var", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /var", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nodev" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e532afe23c6f5187c2f70e28719e78ab", "name": "1.1.2.4.3 — Ensure nosuid option set on /var partition", "description": "Ensure nosuid option set on /var partition", "rational": "Since the /var filesystem is only intended for variable files such as logs, set this option \nto ensure that users cannot create setuid files in /var.", "remediation": "- IF - a separate partition exists for /var. \nEdit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the \n/var partition. \nExample: \n\n /var defaults,rw,nosuid,nodev,noexec,relatime 0 0 \n\nRun the following command to remount /var with the configured options: \n\n# mount -o remount /var", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /var", "selement": "OUTPUT", "condition": "CONTAINS", "sinput": "nosuid" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "a9b22ce98a90f91a340fccdc998fb28e", "name": "1.1.2.6.1 — Ensure separate partition exists for /var/log", "description": "Ensure separate partition exists for /var/log", "rational": "The default installation only creates a single / partition. Since the /var/log directory \ncontains log files which can grow quite large, there is a risk of resource exhaustion. It \nwill essentially have the whole disk available to fill up and impact the system as a whole. \n\nConfiguring /var/log as its own file system allows an administrator to set additional \nmount options such as noexec/nosuid...", "remediation": "For new installations, during installation create a custom partition setup and specify a \nseparate partition for /var/log . \nFor systems that were previously installed, create a new partition and configure \n/etc/fstab as appropriate. \n\nPage 121", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "findmnt -kn /var/log", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "7c949acfc2df6c77d6f1eab93346c1d3", "name": "1.3.1.1 — Ensure AppArmor is installed", "description": "Ensure AppArmor is installed", "rational": "Without a Mandatory Access Control system installed only the default Discretionary \nAccess Control system will be available.", "remediation": "Install AppArmor. \n\n# apt install apparmor apparmor-utils", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "apparmor", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "90fc5f36185b17e7a520603912f26104", "name": "1.4.1 — Ensure bootloader password is set", "description": "Ensure bootloader password is set", "rational": "Requiring a boot password upon execution of the boot loader will prevent an \nunauthorized user from entering boot parameters or changing the boot partition. This \nprevents users from weakening security (e.g. turning off AppArmor at boot time).", "remediation": "Create an encrypted password with grub-mkpasswd-pbkdf2: \n\n# grub-mkpasswd-pbkdf2 --iteration-count=600000 --salt=64 \n\nEnter password: \nReenter password: \nPBKDF2 hash of your password is \n\nAdd the following into a custom /etc/grub.d configuration file: \n\ncat <\" \npassword_pbkdf2 \nEOF \n\nThe superuser/user information and password should not be contained in the \n/etc/grub...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep \"^set superusers\" /boot/grub/grub.cfg", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "2718ac4e26005e5b2bcc7794a5cd63b1", "name": "1.5.2 — Ensure ptrace_scope is restricted", "description": "Ensure ptrace_scope is restricted", "rational": "If one application is compromised, it would be possible for an attacker to attach to other \nrunning processes (e.g. Bash, Firefox, SSH sessions, GPG agent, etc) to extract \nadditional credentials and continue to expand the scope of their attack. \n\nEnabling restricted mode will limit the ability of a compromised process to \nPTRACE_ATTACH on other processes running under the same user. With restr...", "remediation": "Set the kernel.yama.ptrace_scope parameter in /etc/sysctl.conf or a file in \n/etc/sysctl.d/ ending in .conf to a value of 1, 2, or 3: \n\nkernel.yama.ptrace_scope = 1 \n - OR - \nkernel.yama.ptrace_scope = 2 \n - OR - \nkernel.yama.ptrace_scope = 3 \n\nExample: \n\n# printf \"%s\\n\" \"kernel.yama.ptrace_scope = 1\" >> /etc/sysctl.d/60-\nkernel_sysctl.conf \n\nRun the following command to set the active kernel parameter: \n\n# sysctl -w kernel.yama.ptrace_scope=1 \n\nNote: \n\n• \n\n• \n\nIf a value of 2 or 3 is p...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "31720ec1ecec37c37f509e0773d38fe5", "name": "1.5.3 — Ensure core dumps are restricted", "description": "Ensure core dumps are restricted", "rational": "Setting a hard limit on core dumps prevents users from overriding the soft variable. If \ncore dumps are required, consider setting limits for user groups (see limits.conf(5) \n). In addition, setting the fs.suid_dumpable variable to 0 will prevent setuid programs \nfrom dumping core.", "remediation": "Add the following line to /etc/security/limits.conf or a \n/etc/security/limits.d/* file: \n\n* hard core 0 \n\nSet the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• fs.suid_dumpable = 0 \n\nExample: \n# printf \"\\n%s\" \"fs.suid_dumpable = 0\" >> /etc/sysctl.d/60-fs_sysctl.conf \n\nRun the following command to set the active kernel parameter: \n\n# sysctl -w fs.suid_dumpable=0 \n\nNote: If these settings appear in a canonically later file, or later in the same file...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -Ps -- '^\\h*\\*\\h+hard\\h+core\\h+0\\b' /etc/security/limits.conf", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9366df02fb17ac4452361ba0467418e4", "name": "1.5.4 — Ensure prelink is not installed", "description": "Ensure prelink is not installed", "rational": "The prelinking feature can interfere with the operation of AIDE, because it changes \nbinaries. Prelinking can also increase the vulnerability of the system if a malicious user \nis able to compromise a common library such as libc.", "remediation": "Run the following command to restore binaries to normal: \n\n# prelink -ua \n\nUninstall prelink using the appropriate package manager or manual installation: \n\n# apt purge prelink", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "prelink", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "4510a64a0c9a5f5a27916487fc76f480", "name": "1.6.4 — Ensure access to /etc/motd is configured", "description": "Ensure access to /etc/motd is configured", "rational": "- IF - the /etc/motd file does not have the correct access configured, it could be \nmodified by unauthorized users with incorrect or misleading information.", "remediation": "Run the following commands to set mode, owner, and group on /etc/motd: \n\n# chown root:root $(readlink -e /etc/motd) \n# chmod u-x,go-wx $(readlink -e /etc/motd) \n\n- OR - \nRun the following command to remove the /etc/motd file: \n\n# rm /etc/motd", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "[ -e /etc/motd ] && stat -Lc 'Access: (%#a/%A) Uid: ( %u/ %U) Gid: { %g/", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "79049024bd0d78e5580c420edfa1e192", "name": "1.6.5 — Ensure access to /etc/issue is configured", "description": "Ensure access to /etc/issue is configured", "rational": "- IF - the /etc/issue file does not have the correct access configured, it could be \nmodified by unauthorized users with incorrect or misleading information.", "remediation": "Run the following commands to set mode, owner, and group on /etc/issue: \n\n# chown root:root $(readlink -e /etc/issue) \n# chmod u-x,go-wx $(readlink -e /etc/issue)", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "stat -Lc 'Access: (%#a/%A) Uid: ( %u/ %U) Gid: { %g/ %G)' /etc/issue", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "aa48600536b95b4651bec03112e921f0", "name": "1.6.6 — Ensure access to /etc/issue.net is configured", "description": "Ensure access to /etc/issue.net is configured", "rational": "- IF - the /etc/issue.net file does not have the correct access configured, it could be \nmodified by unauthorized users with incorrect or misleading information.", "remediation": "Run the following commands to set mode, owner, and group on /etc/issue.net: \n\n# chown root:root $(readlink -e /etc/issue.net) \n# chmod u-x,go-wx $(readlink -e /etc/issue.net)", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "stat -Lc 'Access: (%#a/%A) Uid: ( %u/ %U) Gid: { %g/ %G)' /etc/issue.net", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c2e7ab3beac6bb6bdb98c049f6f7ab0b", "name": "1.7.2 — Ensure GDM login banner is configured", "description": "Ensure GDM login banner is configured", "rational": "Warning messages inform users who are attempting to login to the system of their legal \nstatus regarding the system and must include the name of the organization that owns \nthe system and any monitoring policies that are in place.", "remediation": "- IF - A user profile is already created run the following commands to set and enable the \ntext banner message on the login screen: \n\n# gsettings set org.gnome.login-screen banner-message-text 'Authorized uses \nonly. All activity may be monitored and reported' \n# gsettings set org.gnome.login-screen banner-message-enable true \n\nNote: \n\n• banner-message-text may be set in accordance with local site policy \n• gsettings commands in this section MUST be done from a command window \n\non a graphic...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "gsettings get org.gnome.login-screen banner-message-enable", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0125c1e79dd3f0bbeb795a86470ccfc8", "name": "1.7.3 — Ensure GDM disable-user-list option is enabled", "description": "Ensure GDM disable-user-list option is enabled", "rational": "Displaying the user list eliminates half of the Userid/Password equation that an \nunauthorized person would need to log on.", "remediation": "- IF - A user profile exists run the following command to enable the disable-user-\nlist: \n\n# gsettings set org.gnome.login-screen disable-user-list true \n\nNote: \n\n• gsettings commands in this section MUST be done from a command window \n\non a graphical desktop or an error will be returned. \n\n• The system must be restarted after all gsettings configurations have been set \n\nin order for CIS-CAT Assessor to appropriately assess. \n\n- OR/IF - A user profile does not exist: \n\n1. Create or edit th...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "gsettings get org.gnome.login-screen disable-user-list", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8aa66b9774b234a0c132cdc2f5df817c", "name": "1.7.8 — Ensure GDM autorun-never is enabled", "description": "Ensure GDM autorun-never is enabled", "rational": "Malware on removable media may taking advantage of Autorun features when the \nmedia is inserted into a system and execute.", "remediation": "- IF - A user profile exists run the following command to set autorun-never to true for \nGDM users: \n\n# gsettings set org.gnome.desktop.media-handling autorun-never true \n\nNote: \n\n• gsettings commands in this section MUST be done from a command window \n\non a graphical desktop or an error will be returned. \n\n• The system must be restarted after all gsettings configurations have been set \n\nin order for CIS-CAT Assessor to appropriately assess. \n\n- OR/IF - A user profile does not exist: \n\n1....", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "gsettings get org.gnome.desktop.media-handling autorun-never", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e902b1f280a624bd737bd04c233932a3", "name": "1.7.9 — Ensure GDM autorun-never is not overridden", "description": "Ensure GDM autorun-never is not overridden", "rational": "Malware on removable media may taking advantage of Autorun features when the \nmedia is inserted into a system and execute. \n\nPage 220", "remediation": "1. To prevent the user from overriding these settings, create the file \n\n/etc/dconf/db/local.d/locks/00-media-autorun with the following content: \n\n[org/gnome/desktop/media-handling] \nautorun-never=true \n\n2. Update the systems databases: \n\n# dconf update \n\nNote: \n\n• A user profile must exist in order to apply locks. \n• Users must log out and back in again before the system-wide settings take effect.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1ce0001239f6e4a9651818b59882c7d8", "name": "1.7.10 — Ensure XDMCP is not enabled", "description": "Ensure XDMCP is not enabled", "rational": "XDMCP is inherently insecure. \n\n• XDMCP is not a ciphered protocol. This may allow an attacker to capture \n\nkeystrokes entered by a user \n\n• XDMCP is vulnerable to man-in-the-middle attacks. This may allow an attacker to \nsteal the credentials of legitimate users by impersonating the XDMCP server.", "remediation": "Edit all files returned by the audit and remove or commend out the Enable=true line in \nthe [xdmcp] block: \nExample file: \n\n# GDM configuration storage \n# \n# See /usr/share/gdm/gdm.schemas for a list of available options. \n\n[daemon] \n# Uncomment the line below to force the login screen to use Xorg \n#WaylandEnable=false \n\n# Enabling automatic login \n# AutomaticLoginEnable = true \n# AutomaticLogin = user1 \n\n# Enabling timed login \n# TimedLoginEnable = true \n# TimedLogin = user1 \n# TimedLog...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c7b66d5591c690b0d16ef76e927adf94", "name": "2.1.1 — Ensure autofs services are not in use", "description": "Ensure autofs services are not in use", "rational": "With automounting enabled anyone with physical access could attach a USB drive or \ndisc and have its contents available in the filesystem even if they lacked permissions to \nmount it themselves.", "remediation": "Run the following commands to stop autofs.service and remove the autofs \npackage: \n\n# systemctl stop autofs.service \n# apt purge autofs \n\n- OR - \n- IF - the autofs package is required as a dependency: \nRun the following commands to stop and mask autofs.service: \n\n# systemctl stop autofs.service \n# systemctl mask autofs.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "autofs", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "243b6057938a64e36acd475c1931e6a0", "name": "2.1.2 — Ensure avahi daemon services are not in use", "description": "Ensure avahi daemon services are not in use", "rational": "Automatic discovery of network services is not normally required for system \nfunctionality. It is recommended to remove this package to reduce the potential attack \nsurface.", "remediation": "Run the following commands to stop avahi-daemon.socket and avahi-\ndaemon.service, and remove the avahi-daemon package: \n\n# systemctl stop avahi-daemon.socket avahi-daemon.service \n# apt purge avahi-daemon \n\n- OR - \n- IF - the avahi-daemon package is required as a dependency: \nRun the following commands to stop and mask the avahi-daemon.socket and avahi-\ndaemon.service: \n\n# systemctl stop avahi-daemon.socket avahi-daemon.service \n# systemctl mask avahi-daemon.socket avahi-daemon.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "avahi-daemon", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "4b8286193304dbd2061755dc839a366a", "name": "2.1.3 — Ensure dhcp server services are not in use", "description": "Ensure dhcp server services are not in use", "rational": "Unless a system is specifically set up to act as a DHCP server, it is recommended that \nthis package be removed to reduce the potential attack surface.", "remediation": "Run the following commands to stop isc-dhcp-server.service and isc-dhcp-\nserver6.service and remove the isc-dhcp-server package: \n\n# systemctl stop isc-dhcp-server.service isc-dhcp-server6.service \n# apt purge isc-dhcp-server \n\n- OR - \n- IF - the isc-dhcp-server package is required as a dependency: \nRun the following commands to stop and mask isc-dhcp-server.service and isc-\ndhcp-server6.service: \n\n# systemctl stop isc-dhcp-server.service isc-dhcp-server6.service \n# systemctl mask isc-dhcp-se...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "isc-dhcp-server", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "5cd9064f97b807e0f06a4a5b24d1d1ff", "name": "2.1.4 — Ensure dns server services are not in use", "description": "Ensure dns server services are not in use", "rational": "Unless a system is specifically designated to act as a DNS server, it is recommended \nthat the package be deleted to reduce the potential attack surface.", "remediation": "Run the following commands to stop named.service and remove the bind9 package: \n\n# systemctl stop named.service \n# apt purge bind9 \n\n- OR - \n- IF - the bind9 package is required as a dependency: \nRun the following commands to stop and mask bind9.service: \n\n# systemctl stop named.service \n# systemctl mask named.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "bind9", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "060d81146b7d9b7834a7f40c0e7b5c69", "name": "2.1.5 — Ensure dnsmasq services are not in use", "description": "Ensure dnsmasq services are not in use", "rational": "Unless a system is specifically designated to act as a DNS caching, DNS forwarding \nand/or DHCP server, it is recommended that the package be removed to reduce the \npotential attack surface.", "remediation": "Run the following commands to stop dnsmasq.service and remove dnsmasq package: \n\n# systemctl stop dnsmasq.service \n# apt purge dnsmasq \n\n- OR - \n- IF - the dnsmasq package is required as a dependency: \nRun the following commands to stop and mask the dnsmasq.service: \n\n# systemctl stop dnsmasq.service \n# systemctl mask dnsmasq.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "dnsmasq", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "dd92bf36e563588e8d3b2e11b402398f", "name": "2.1.6 — Ensure ftp server services are not in use", "description": "Ensure ftp server services are not in use", "rational": "FTP does not protect the confidentiality of data or authentication credentials. It is \nrecommended SFTP be used if file transfer is required. Unless there is a need to run \nthe system as a FTP server (for example, to allow anonymous downloads), it is \nrecommended that the package be deleted to reduce the potential attack surface.", "remediation": "Run the following commands to stop vsftpd.service and remove the vsftpd \npackage: \n\n# systemctl stop vsftpd.service \n# apt purge vsftpd \n\n- OR - \n- IF - the vsftpd package is required as a dependency: \nRun the following commands to stop and mask the vsftpd.service: \n\n# systemctl stop vsftpd.service \n# systemctl mask vsftpd.service \n\nNote: Other ftp server packages may exist. If not required and authorized by local site \npolicy, they should also be removed. If the package is required for a dep...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "vsftpd", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "7a0d9391ff2160181314105bdf8d0e7e", "name": "2.1.7 — Ensure ldap server services are not in use", "description": "Ensure ldap server services are not in use", "rational": "If the system will not need to act as an LDAP server, it is recommended that the \nsoftware be removed to reduce the potential attack surface.", "remediation": "Run the following commands to stop slapd.service and remove the slapd package: \n\n# systemctl stop slapd.service \n# apt purge slapd \n\n- OR - \n- IF - the slapd package is required as a dependency: \nRun the following commands to stop and mask slapd.service: \n\n# systemctl stop slapd.service \n# systemctl mask slapd.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "slapd", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c240a7e02e545568bdb38da79916b18a", "name": "2.1.10 — Ensure nis server services are not in use", "description": "Ensure nis server services are not in use", "rational": "ypserv.service is inherently an insecure system that has been vulnerable to DOS \nattacks, buffer overflows and has poor authentication for querying NIS maps. NIS \ngenerally has been replaced by such protocols as Lightweight Directory Access \nProtocol (LDAP). It is recommended that ypserv.service be removed and other, more \nsecure services be used", "remediation": "Run the following commands to stop ypserv.service and remove ypserv package: \n\n# systemctl stop ypserv.service \n# apt purge ypserv \n\n- OR - \n- IF - the ypserv package is required as a dependency: \nRun the following commands to stop and mask ypserv.service: \n\n# systemctl stop ypserv.service \n# systemctl mask ypserv.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "ypserv", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "60ed74ad38de7faf1e5004d7795a63e3", "name": "2.1.11 — Ensure print server services are not in use", "description": "Ensure print server services are not in use", "rational": "If the system does not need to print jobs or accept print jobs from other systems, it is \nrecommended that CUPS be removed to reduce the potential attack surface.", "remediation": "Run the following commands to stop cups.socket and cups.service, and remove the \ncups package: \n\n# systemctl stop cups.socket cups.service \n# apt purge cups \n\n- OR - \n- IF - the cups package is required as a dependency: \nRun the following commands to stop and mask the cups.socket and cups.service: \n\n# systemctl stop cups.socket cups.service \n# systemctl mask cups.socket cups.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "cups", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "342388a3553d51437bf2a1b056fca942", "name": "2.1.12 — Ensure rpcbind services are not in use", "description": "Ensure rpcbind services are not in use", "rational": "A small request (~82 bytes via UDP) sent to the Portmapper generates a large \nresponse (7x to 28x amplification), which makes it a suitable tool for DDoS attacks. If \nrpcbind is not required, it is recommended to remove rpcbind package to reduce the \npotential attack surface.", "remediation": "Run the following commands to stop rpcbind.socket and rpcbind.service, and \nremove the rpcbind package: \n\n# systemctl stop rpcbind.socket rpcbind.service \n# apt purge rpcbind \n\n- OR - \n- IF - the rpcbind package is required as a dependency: \nRun the following commands to stop and mask the rpcbind.socket and \nrpcbind.service: \n\n# systemctl stop rpcbind.socket rpcbind.service \n# systemctl mask rpcbind.socket rpcbind.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "rpcbind", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1f83722c70ba7e3347a2937458a9377c", "name": "2.1.13 — Ensure rsync services are not in use", "description": "Ensure rsync services are not in use", "rational": "rsync.service presents a security risk as the rsync protocol is unencrypted. \n\nThe rsync package should be removed to reduce the attack area of the system.", "remediation": "Run the following commands to stop rsync.service, and remove the rsync package: \n\n# systemctl stop rsync.service \n# apt purge rsync \n\n- OR - \n- IF - the rsync package is required as a dependency: \nRun the following commands to stop and mask rsync.service: \n\n# systemctl stop rsync.service \n# systemctl mask rsync.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "rsync", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "eea95dc21e64723571b3f4f7d89ae1ae", "name": "2.1.15 — Ensure snmp services are not in use", "description": "Ensure snmp services are not in use", "rational": "The SNMP server can communicate using SNMPv1, which transmits data in the clear \nand does not require authentication to execute commands. SNMPv3 replaces the \nsimple/clear text password sharing used in SNMPv2 with more securely encoded \nparameters. If the the SNMP service is not required, the snmpd package should be \nremoved to reduce the attack surface of the system. \n\nNote: If SNMP is require...", "remediation": "Run the following commands to stop snmpd.service and remove the snmpd package: \n\n# systemctl stop snmpd.service \n# apt purge snmpd \n\n- OR - If the package is required for dependencies: \nRun the following commands to stop and mask the snmpd.service: \n\n# systemctl stop snmpd.service \n# systemctl mask snmpd.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "snmpd", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "ec708beefd6058471dec266f5ae92e99", "name": "2.1.16 — Ensure tftp server services are not in use", "description": "Ensure tftp server services are not in use", "rational": "Unless there is a need to run the system as a TFTP server, it is recommended that the \npackage be removed to reduce the potential attack surface. \n\nTFTP does not have built-in encryption, access control or authentication. This makes it \nvery easy for an attacker to exploit TFTP to gain access to files", "remediation": "Run the following commands to stop tftpd-hpa.service, and remove the tftpd-hpa \npackage: \n\n# systemctl stop tftpd-hpa.service \n# apt purge tftpd-hpa \n\n- OR - \n- IF - the tftpd-hpa package is required as a dependency: \nRun the following commands to stop and mask tftpd-hpa.service: \n\n# systemctl stop tftpd-hpa.service \n# systemctl mask tftpd-hpa.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "tftpd-hpa", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "a433e30633295d90761a2d8c19e9c5c4", "name": "2.1.18 — Ensure web server services are not in use", "description": "Ensure web server services are not in use", "rational": "Unless there is a local site approved requirement to run a web server service on the \nsystem, web server packages should be removed to reduce the potential attack surface.", "remediation": "Run the following commands to stop httpd.socket, httpd.service, and \nnginx.service, and remove apache2 and nginx packages: \n\n# systemctl stop apache2.socket apache2.service nginx.service \n# apt purge apache2 nginx \n\n- OR - \n- IF - a package is installed and is required for dependencies: \nRun the following commands to stop and mask apache2.socket, apache2.service, \nand nginx.service: \n\n# systemctl stop apache2.socket apache2.service nginx.service \n# systemctl mask apache2.socket apache2.servic...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "apache2", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8a882c2eacfd082182deb22a983c6c12", "name": "2.1.19 — Ensure xinetd services are not in use", "description": "Ensure xinetd services are not in use", "rational": "If there are no xinetd services required, it is recommended that the package be \nremoved to reduce the attack surface are of the system. \n\nNote: If an xinetd service or services are required, ensure that any xinetd service not \nrequired is stopped and masked", "remediation": "Run the following commands to stop xinetd.service, and remove the xinetd \npackage: \n\n# systemctl stop xinetd.service \n# apt purge xinetd \n\n-OR- \n-IF- the xinetd package is required as a dependency: \nRun the following commands to stop and mask the xinetd.service: \n\n# systemctl stop xinetd.service \n# systemctl mask xinetd.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "xinetd", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "4a0ffe09ed052a143e8526294f95cedb", "name": "2.2.1 — Ensure NIS Client is not installed", "description": "Ensure NIS Client is not installed", "rational": "The NIS service is inherently an insecure system that has been vulnerable to DOS \nattacks, buffer overflows and has poor authentication for querying NIS maps. NIS \ngenerally has been replaced by such protocols as Lightweight Directory Access \nProtocol (LDAP). It is recommended that the service be removed.", "remediation": "Uninstall nis: \n\n# apt purge nis", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "nis", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "29496007e87d3286ddaae095c5e55e76", "name": "2.2.2 — Ensure rsh client is not installed", "description": "Ensure rsh client is not installed", "rational": "These legacy clients contain numerous security exposures and have been replaced with \nthe more secure SSH package. Even if the server is removed, it is best to ensure the \nclients are also removed to prevent users from inadvertently attempting to use these \ncommands and therefore exposing their credentials. Note that removing the rsh-\nclient package removes the clients for rsh , rcp and rlogin .", "remediation": "Uninstall rsh: \n\n# apt purge rsh-client", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "rsh-client", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8e03060e2ec22ec8e49c70274e18ff0d", "name": "2.2.3 — Ensure talk client is not installed", "description": "Ensure talk client is not installed", "rational": "The software presents a security risk as it uses unencrypted protocols for \ncommunication.", "remediation": "Uninstall talk: \n\n# apt purge talk", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "talk", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "3f4181a3ba354acba32a42d98e2def8d", "name": "2.2.4 — Ensure telnet client is not installed", "description": "Ensure telnet client is not installed", "rational": "The telnet protocol is insecure and unencrypted. The use of an unencrypted \ntransmission medium could allow an unauthorized user to steal credentials. The ssh \npackage provides an encrypted session and stronger security and is included in most \nLinux distributions.", "remediation": "Run the following commands to uninstall telnet & inetutils-telnet: \n\n# apt purge telnet \n# apt purge inetutils-telnet", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "dpkg-query -l | grep -E 'telnet|inetutils-telnet' &>/dev/null && echo", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e16ffc9cf7f3d70b8075f3af7f0ef3bf", "name": "2.2.5 — Ensure ldap client is not installed", "description": "Ensure ldap client is not installed", "rational": "If the system will not need to act as an LDAP client, it is recommended that the software \nbe removed to reduce the potential attack surface.", "remediation": "Uninstall ldap-utils: \n\n# apt purge ldap-utils", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "ldap-utils", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "cb00b77539d4b775f39f6d9f4492cf8d", "name": "2.2.6 — Ensure ftp client is not installed", "description": "Ensure ftp client is not installed", "rational": "Unless there is a need to run the system using Internet standard File Transfer Protocol \n(for example, to allow anonymous downloads), it is recommended that the package be \nremoved to reduce the potential attack surface.", "remediation": "Run the following commands to uninstall tnftp & ftp: \n\n# apt purge ftp \n# apt purge tnftp", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "dpkg-query -l | grep -E 'ftp|tnftp' &>/dev/null && echo \"ftp is installed\"", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "bc57275f7565e8cc3f27160eb5ea5ae2", "name": "2.3.3.2 — Ensure chrony is running as user _chrony", "description": "Ensure chrony is running as user _chrony", "rational": "The chronyd service should run with only the required privlidges", "remediation": "Add or edit the user line to /etc/chrony/chrony.conf or a file ending in .conf in \n/etc/chrony/conf.d/: \n\nuser _chrony \n\n- OR - \nIf another time synchronization service is in use on the system, run the following \ncommand to remove chrony from the system: \n\n# apt purge chrony \n# apt autoremove chrony", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PROCESS", "input": "chronyd", "selement": "OWNER", "condition": "EQUALS", "sinput": "_chrony" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "37af07e1ab3a4c835e0e450588940140", "name": "2.3.3.3 — Ensure chrony is enabled and running", "description": "Ensure chrony is enabled and running", "rational": "chrony needs to be enabled and running in order to synchronize the system to a \ntimeserver. \n\nTime synchronization is important to support time sensitive security mechanisms and to \nensure log files have consistent time records across the enterprise to aid in forensic \ninvestigations", "remediation": "- IF - chrony is in use on the system, run the following commands: \nRun the following command to unmask chrony.service: \n\n# systemctl unmask chrony.service \n\nRun the following command to enable and start chrony.service: \n\n# systemctl --now enable chrony.service \n\n- OR - \nIf another time synchronization service is in use on the system, run the following \ncommand to remove chrony: \n\n# apt purge chrony \n# apt autoremove chrony", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "chrony", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "5db6ba85e5feda950650c3f840a8637c", "name": "2.4.1.1 — Ensure cron daemon is enabled and active", "description": "Ensure cron daemon is enabled and active", "rational": "While there may not be user jobs that need to be run on the system, the system does \nhave maintenance jobs that may include security monitoring that have to run, and cron \nis used to execute them.", "remediation": "- IF - cron is installed on the system: \nRun the following commands to unmask, enable, and start cron: \n\n# systemctl unmask \"$(systemctl list-unit-files | awk \n'$1~/^crond?\\.service/{print $1}')\" \n# systemctl --now enable \"$(systemctl list-unit-files | awk \n'$1~/^crond?\\.service/{print $1}')\"", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "systemctl list-unit-files | awk '$1~/^crond?\\.service/{print $2}'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0ccb1689370049078a7c0b361472ef6b", "name": "2.4.2.1 — Ensure at is restricted to authorized users", "description": "Ensure at is restricted to authorized users", "rational": "On many systems, only the system administrator is authorized to schedule at jobs. \nUsing the at.allow file to control who can run at jobs enforces this policy. It is easier \nto manage an allow list than a deny list. In a deny list, you could potentially add a user \nID to the system and forget to add it to the deny files. \n\nPage 348", "remediation": "- IF - at is installed on the system: \nRun the following script to: \n\n• /etc/at.allow: \n\no Create the file if it doesn't exist \no Change owner or user root \no \n\nIf group daemon exists, change to group daemon, else change group to \nroot \n\no Change mode to 640 or more restrictive \n\n• \n\n- IF - /etc/at.deny exists: \n\no Change owner or user root \no \n\nIf group daemon exists, change to group daemon, else change group to \nroot \n\no Change mode to 640 or more restrictive \n\n#!/usr/bin/env bash \n\n{...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "stat -Lc 'Access: (%a/%A) Owner: (%U) Group: (%G)' /etc/at.allow", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "593aad0a5cdcd2688cf0b7d721fcf340", "name": "3.1.2 — Ensure wireless interfaces are disabled", "description": "Ensure wireless interfaces are disabled", "rational": "-IF- wireless is not to be used, wireless devices can be disabled to reduce the potential \nattack surface.", "remediation": "Run the following script to disable any wireless interfaces: \n\n#!/usr/bin/env bash \n\n{ \n module_fix() \n { \n if ! modprobe -n -v \"$l_mname\" | grep -P -- '^\\h*install \n\\/bin\\/(true|false)'; then \n echo -e \" - setting module: \\\"$l_mname\\\" to be un-loadable\" \n echo -e \"install $l_mname /bin/false\" >> \n/etc/modprobe.d/\"$l_mname\".conf \n fi \n if lsmod | grep \"$l_mname\" > /dev/null 2>&1; then \n echo -e \" - unloading module \\\"$l_mname\\\"\" \n modprobe -r...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "036880d0ddf59f091de48c28cf568aad", "name": "3.1.3 — Ensure bluetooth services are not in use", "description": "Ensure bluetooth services are not in use", "rational": "An attacker may be able to find a way to access or corrupt your data. One example of \nthis type of activity is bluesnarfing, which refers to attackers using a Bluetooth \nconnection to steal information off of your Bluetooth device. Also, viruses or other \nmalicious code can take advantage of Bluetooth technology to infect other devices. If \nyou are infected, your data may be corrupted, compromi...", "remediation": "Run the following commands to stop bluetooth.service, and remove the bluez \npackage: \n\n# systemctl stop bluetooth.service \n# apt purge bluez \n\n- OR - \n- IF - the bluez package is required as a dependency: \nRun the following commands to stop and mask bluetooth.service: \n\n# systemctl stop bluetooth.service \n# systemctl mask bluetooth.service \n\nNote: A reboot may be required", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "bluez", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e82fe545b2ef27bd90e5d776fc29ad1d", "name": "3.3.1 — Ensure ip forwarding is disabled", "description": "Ensure ip forwarding is disabled", "rational": "Setting net.ipv4.ip_forward and net.ipv6.conf.all.forwarding to 0 ensures \nthat a system with multiple interfaces (for example, a hard proxy), will never be able to \nforward packets, and therefore, never serve as a router.", "remediation": "Set the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.ip_forward = 0 \n\nExample: \n# printf '%s\\n' \"net.ipv4.ip_forward = 0\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.ip_forward=0 \n sysctl -w net.ipv4.route.flush=1 \n} \n\n- IF - IPv6 is enabled on the system: \nSet the following parameter in /etc/sysctl.conf or a file in /etc/sysctl...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8a1321a258b76d0424b1a907ac58545c", "name": "3.3.2 — Ensure packet redirect sending is disabled", "description": "Ensure packet redirect sending is disabled", "rational": "An attacker could use a compromised host to send invalid ICMP redirects to other \nrouter devices in an attempt to corrupt routing and have users access a system set up \nby the attacker as opposed to a valid system.", "remediation": "Set the following parameters in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.conf.all.send_redirects = 0 \n• net.ipv4.conf.default.send_redirects = 0 \n\nExample: \n# printf '%s\\n' \"net.ipv4.conf.all.send_redirects = 0\" \n\"net.ipv4.conf.default.send_redirects = 0\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.conf.all.send_redirects=0 \n sysctl -w net.ipv4.c...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "ec628b8cbafe8d589b98fd8bf2308678", "name": "3.3.3 — Ensure bogus icmp responses are ignored", "description": "Ensure bogus icmp responses are ignored", "rational": "Some routers (and some attackers) will send responses that violate RFC-1122 and \nattempt to fill up a log file system with many useless error messages.", "remediation": "Set the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.icmp_ignore_bogus_error_responses = 1 \n\nExample: \n# printf '%s\\n' \"net.ipv4.icmp_ignore_bogus_error_responses = 1\" >> \n/etc/sysctl.d/60-netipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1 \n sysctl -w net.ipv4.route.flush=1 \n} \n\nNote: If these settings appear in a canoni...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "cfd6775a3c4cab1b07a44fdb189c2704", "name": "3.3.4 — Ensure broadcast icmp requests are ignored", "description": "Ensure broadcast icmp requests are ignored", "rational": "Accepting ICMP echo and timestamp requests with broadcast or multicast destinations \nfor your network could be used to trick your host into starting (or participating) in a \nSmurf attack. A Smurf attack relies on an attacker sending large amounts of ICMP \nbroadcast messages with a spoofed source address. All hosts receiving this message \nand responding would send echo-reply messages back to the...", "remediation": "Set the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.icmp_echo_ignore_broadcasts = 1 \n\nExample: \n# printf '%s\\n' \"net.ipv4.icmp_echo_ignore_broadcasts = 1\" >> \n/etc/sysctl.d/60-netipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1 \n sysctl -w net.ipv4.route.flush=1 \n} \n\nNote: If these settings appear in a canonically later file,...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8fde0e42e623b231801ef382a5a03ddc", "name": "3.3.5 — Ensure icmp redirects are not accepted", "description": "Ensure icmp redirects are not accepted", "rational": "ICMP redirect messages are packets that convey routing information and tell your host \n(acting as a router) to send packets via an alternate path. It is a way of allowing an \noutside routing device to update your system routing tables. By setting \nnet.ipv4.conf.all.accept_redirects, \nnet.ipv4.conf.default.accept_redirects, \nnet.ipv6.conf.all.accept_redirects, and \nnet.ipv6.conf.default.accept_r...", "remediation": "Set the following parameters in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.conf.all.accept_redirects = 0 \n• net.ipv4.conf.default.accept_redirects = 0 \n\nExample: \n# printf '%s\\n' \"net.ipv4.conf.all.accept_redirects = 0\" \n\"net.ipv4.conf.default.accept_redirects = 0\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.conf.all.accept_redirects=0 \n sysctl -w...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9535cd723a62765c374e532bbea18e05", "name": "3.3.6 — Ensure secure icmp redirects are not accepted", "description": "Ensure secure icmp redirects are not accepted", "rational": "It is still possible for even known gateways to be compromised. Setting \nnet.ipv4.conf.all.secure_redirects and \nnet.ipv4.conf.default.secure_redirects to 0 protects the system from routing \ntable updates by possibly compromised known gateways.", "remediation": "Set the following parameters in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.conf.all.secure_redirects = 0 \n• net.ipv4.conf.default.secure_redirects = 0 \n\nExample: \n# printf '%s\\n' \"net.ipv4.conf.all.secure_redirects = 0\" \n\"net.ipv4.conf.default.secure_redirects = 0\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.conf.all.secure_redirects=0 \n sysctl -w...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "7c5cace1ecf6299b62816903dd586ac2", "name": "3.3.7 — Ensure reverse path filtering is enabled", "description": "Ensure reverse path filtering is enabled", "rational": "Setting net.ipv4.conf.all.rp_filter and net.ipv4.conf.default.rp_filter to \n1 is a good way to deter attackers from sending your system bogus packets that cannot \nbe responded to. One instance where this feature breaks down is if asymmetrical \nrouting is employed. This would occur when using dynamic routing protocols (bgp, ospf, \netc) on your system. If you are using asymmetrical routing on you...", "remediation": "Set the following parameters in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.conf.all.rp_filter = 1 \n• net.ipv4.conf.default.rp_filter = 1 \n\nExample: \n# printf '%s\\n' \"net.ipv4.conf.all.rp_filter = 1\" \n\"net.ipv4.conf.default.rp_filter = 1\" >> /etc/sysctl.d/60-netipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.conf.all.rp_filter=1 \n sysctl -w net.ipv4.conf.default.rp_filter=1...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "fde1aa12ab981a4b21b509cfdba8dfe5", "name": "3.3.9 — Ensure suspicious packets are logged", "description": "Ensure suspicious packets are logged", "rational": "Setting net.ipv4.conf.all.log_martians and \nnet.ipv4.conf.default.log_martians to 1 enables this feature. Logging these \npackets allows an administrator to investigate the possibility that an attacker is sending \nspoofed packets to their system.", "remediation": "Set the following parameters in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.conf.all.log_martians = 1 \n• net.ipv4.conf.default.log_martians = 1 \n\nExample: \n# printf '%s\\n' \"net.ipv4.conf.all.log_martians = 1\" \n\"net.ipv4.conf.default.log_martians = 1\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.conf.all.log_martians=1 \n sysctl -w net.ipv4.conf.defaul...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "925fda8f3dbb56168b07601b8546e05b", "name": "3.3.10 — Ensure tcp syn cookies is enabled", "description": "Ensure tcp syn cookies is enabled", "rational": "Attackers use SYN flood attacks to perform a denial of service attacked on a system by \nsending many SYN packets without completing the three way handshake. This will \nquickly use up slots in the kernel's half-open connection queue and prevent legitimate \nconnections from succeeding. Setting net.ipv4.tcp_syncookies to 1 enables SYN \ncookies, allowing the system to keep accepting valid connectio...", "remediation": "Set the following parameter in /etc/sysctl.conf or a file in /etc/sysctl.d/ ending \nin .conf: \n\n• net.ipv4.tcp_syncookies = 1 \n\nExample: \n# printf '%s\\n' \"net.ipv4.tcp_syncookies = 1\" >> /etc/sysctl.d/60-\nnetipv4_sysctl.conf \n\nRun the following script to set the active kernel parameters: \n\n#!/usr/bin/env bash \n\n{ \n sysctl -w net.ipv4.tcp_syncookies=1 \n sysctl -w net.ipv4.route.flush=1 \n} \n\nNote: If these settings appear in a canonically later file, or later in the same file, these \nsetti...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "ce4574a8cc9f4fa555887c6c7e797a5b", "name": "4.2.1 — Ensure ufw is installed", "description": "Ensure ufw is installed", "rational": "A firewall utility is required to configure the Linux kernel's netfilter framework via the \niptables or nftables back-end. \n\nThe Linux kernel's netfilter framework host-based firewall can protect against threats \noriginating from within a corporate network to include malicious mobile code and poorly \nconfigured software on a host. \n\nNote: Only one firewall utility should be installed and config...", "remediation": "Run the following command to install Uncomplicated Firewall (UFW): \n\n# apt install ufw", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "ufw", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "ca6dc222fd748836fea18f2c6a970373", "name": "4.2.3 — Ensure ufw service is enabled", "description": "Ensure ufw service is enabled", "rational": "The ufw service must be enabled and running in order for ufw to protect the system", "remediation": "Run the following command to unmask the ufw daemon: \n\n# systemctl unmask ufw.service \n\nRun the following command to enable and start the ufw daemon: \n\n# systemctl --now enable ufw.service \n\nactive \n\nRun the following command to enable ufw: \n\n# ufw enable", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "ufw", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "596f627659b672919f60e11dfc21d58d", "name": "4.2.4 — Ensure ufw loopback traffic is configured", "description": "Ensure ufw loopback traffic is configured", "rational": "Loopback traffic is generated between processes on machine and is typically critical to \noperation of the system. The loopback interface is the only place that loopback network \n(127.0.0.0/8 for IPv4 and ::1/128 for IPv6) traffic should be seen, all other interfaces \nshould ignore traffic on this network as an anti-spoofing measure.", "remediation": "Run the following commands to configure the loopback interface to accept traffic: \n\n# ufw allow in on lo \n# ufw allow out on lo \n\nRun the following commands to configure all other interfaces to deny traffic to the \nloopback network: \n\n# ufw deny in from 127.0.0.0/8 \n# ufw deny in from ::1", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -P -- 'lo|127.0.0.0' /etc/ufw/before.rules", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "aac6535b74a7b61c3ac56666ebb52820", "name": "4.2.6 — Ensure ufw firewall rules exist for all open ports", "description": "Ensure ufw firewall rules exist for all open ports", "rational": "To reduce the attack surface of a system, all services and ports should be blocked \nunless required. \n\n• Any ports that have been opened on non-loopback addresses need firewall rules \n\nto govern traffic. \n\n• Without a firewall rule configured for open ports, the default firewall policy will \n\ndrop all packets to these ports. \n\n• Required ports should have a firewall rule created to allow app...", "remediation": "For each port identified in the audit which does not have a firewall rule, evaluate the \nservice listening on the port and add a rule for accepting or denying inbound \nconnections in accordance with local site policy: \nExamples: \n\n# ufw allow in / \n\n# ufw deny in / \n\nNote: Examples create rules for from any, to any. More specific rules should be \nconcentered when allowing inbound traffic e.g only traffic from this network. \nExample to allo...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "533274086547940a7ff56ab7586c80b8", "name": "4.2.7 — Ensure ufw default deny firewall policy", "description": "Ensure ufw default deny firewall policy", "rational": "With a default accept policy the firewall will accept any packet that is not configured to \nbe denied. It is easier to allow list acceptable usage than to deny list unacceptable \nusage.", "remediation": "Run the following commands to implement a default deny policy: \n\n# ufw default deny incoming \n# ufw default deny outgoing \n# ufw default deny routed", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "ufw status verbose | grep Default:", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "00e5f3bc977a90d4e349e8f2cc0764bf", "name": "4.3.1 — Ensure nftables is installed", "description": "Ensure nftables is installed", "rational": "nftables is a subsystem of the Linux kernel that can protect against threats originating \nfrom within a corporate network to include malicious mobile code and poorly configured \nsoftware on a host.", "remediation": "Run the following command to install nftables: \n\n# apt install nftables", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "nftables", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "89f5e7700eb9741b48fcdf9d8916ec87", "name": "4.3.4 — Ensure a nftables table exists", "description": "Ensure a nftables table exists", "rational": "nftables doesn't have any default tables. Without a table being built, nftables will not \nfilter network traffic.", "remediation": "Run the following command to create a table in nftables \n\n# nft create table inet \n\nExample: \n\n# nft create table inet filter", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "nft list tables", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "f2dc723d251827ea3d2d47ac5c5ec676", "name": "4.3.5 — Ensure nftables base chains exist", "description": "Ensure nftables base chains exist", "rational": "If a base chain doesn't exist with a hook for input, forward, and delete, packets that \nwould flow through those chains will not be touched by nftables.", "remediation": "Run the following command to create the base chains: \n\n# nft create chain inet
{ type filter hook \n<(input|forward|output)> priority 0 \\; } \n\nExample: \n\n# nft create chain inet filter input { type filter hook input priority 0 \\; } \n\n# nft create chain inet filter forward { type filter hook forward priority 0 \n\\; } \n\n# nft create chain inet filter output { type filter hook output priority 0 \\; \n}", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "nft list ruleset | grep 'hook input'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c71928db22713e01f3a742e4e09c4d1c", "name": "4.3.6 — Ensure nftables loopback traffic is configured", "description": "Ensure nftables loopback traffic is configured", "rational": "Loopback traffic is generated between processes on machine and is typically critical to \nthe operation of the system. The loopback interface is the only place that loopback \nnetwork traffic should be seen, all other interfaces should ignore traffic on this network \nas an anti-spoofing measure.", "remediation": "Run the following commands to implement the loopback rules: \n\n# nft add rule inet filter input iif lo accept \n# nft add rule inet filter input ip saddr 127.0.0.0/8 counter drop \n\n- IF - IPv6 is enabled on the system: \nRun the following command to implement the IPv6 loopback rule: \n\n# nft add rule inet filter input ip6 saddr ::1 counter drop", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "nft list ruleset | awk '/hook input/,/}/' | grep 'iif \"lo\" accept'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8c3a1798e28c1b646fc59156e58005ec", "name": "4.3.8 — Ensure nftables default deny firewall policy", "description": "Ensure nftables default deny firewall policy", "rational": "There are two policies: accept (Default) and drop. If the policy is set to accept, the \nfirewall will accept any packet that is not configured to be denied and the packet will \ncontinue transversing the network stack. \n\nIt is easier to allow list acceptable usage than to deny list unacceptable usage. \n\nNote: \n\n• Allow port 22(ssh) needs to be updated to only allow systems requiring ssh \n\nconne...", "remediation": "Run the following command for the base chains with the input, forward, and output \nhooks to implement a default DROP policy: \n\n# nft chain
{ policy drop \\; } \n\nExample: \n\n# nft chain inet filter input { policy drop \\; } \n\n# nft chain inet filter forward { policy drop \\; } \n\n# nft chain inet filter output { policy drop \\; }", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "nft list ruleset | grep 'hook input'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8d811a5a1aa8e06f1b66702b065ef852", "name": "4.3.9 — Ensure nftables service is enabled", "description": "Ensure nftables service is enabled", "rational": "The nftables service restores the nftables rules from the rules files referenced in the \n/etc/nftables.conf file during boot or the starting of the nftables service", "remediation": "Run the following command to enable the nftables service: \n\n# systemctl enable nftables", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "nftables", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6553a49da36563b35e3c3be90f50a0c2", "name": "4.3.10 — Ensure nftables rules are permanent", "description": "Ensure nftables rules are permanent", "rational": "Changes made to nftables ruleset only affect the live system, you will also need to \nconfigure the nftables ruleset to apply on boot \n\nPage 485", "remediation": "Edit the /etc/nftables.conf file and un-comment or add a line with include \n for each nftables file you want included \nin the nftables ruleset on boot \nExample: \n\n# vi /etc/nftables.conf \n\nAdd the line: \n\ninclude \"/etc/nftables.rules\"", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "[ -n \"$(grep -E '^\\s*include' /etc/nftables.conf)\" ] && awk '/hook", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6a88473f6cb635ef2827e11ce9837e92", "name": "4.4.1.1 — Ensure iptables packages are installed", "description": "Ensure iptables packages are installed", "rational": "A method of configuring and maintaining firewall rules is necessary to configure a Host \nBased Firewall.", "remediation": "Run the following command to install iptables and iptables-persistent \n\n# apt install iptables iptables-persistent", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "iptables", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "779f469f328511d371f455ece0524c97", "name": "4.4.1.2 — Ensure nftables is not in use with iptables", "description": "Ensure nftables is not in use with iptables", "rational": "Running both iptables and nftables may lead to conflict.", "remediation": "Run the following command to remove nftables: \n\n# apt purge nftables \n\n- OR - \nRun the following commands to stop and mask nftables.service: \n\n# systemctl stop nftables.service \n# systemctl mask nftables.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "nftables", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6b6efc799954091290c717e8cda4a92b", "name": "4.4.1.3 — Ensure ufw is not in use with iptables", "description": "Ensure ufw is not in use with iptables", "rational": "Running iptables.persistent with ufw enabled may lead to conflict and unexpected \nresults.", "remediation": "Run the following command to remove ufw: \n\n# apt purge ufw \n\n- OR - \nRun the following commands to disable ufw, and stop and mask ufw.service: \n\n# ufw disable \n# systemctl stop ufw.service \n# systemctl mask ufw.service \n\nNote: ufw disable needs to be run before systemctl mask ufw.service in order to \ncorrectly disable UFW", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "ufw", "selement": "NOT EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "57bab3e078b62081246e18735e239a91", "name": "4.4.2.1 — Ensure iptables default deny firewall policy", "description": "Ensure iptables default deny firewall policy", "rational": "With a default accept policy the firewall will accept any packet that is not configured to \nbe denied. It is easier to allow list acceptable usage than to deny list unacceptable \nusage.", "remediation": "Run the following commands to implement a default DROP policy: \n\n# iptables -P INPUT DROP \n# iptables -P OUTPUT DROP \n# iptables -P FORWARD DROP", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "iptables -L", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "043ec60a3bf48fde6ad988465b4aace2", "name": "4.4.2.2 — Ensure iptables loopback traffic is configured", "description": "Ensure iptables loopback traffic is configured", "rational": "Loopback traffic is generated between processes on machine and is typically critical to \nthe operation of the system. The loopback interface is the only place that loopback \nnetwork (127.0.0.0/8) traffic should be seen, all other interfaces should ignore traffic on \nthis network as an anti-spoofing measure.", "remediation": "Run the following commands to implement the loopback rules: \n\n# iptables -A INPUT -i lo -j ACCEPT \n# iptables -A OUTPUT -o lo -j ACCEPT \n# iptables -A INPUT -s 127.0.0.0/8 -j DROP", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "iptables -L INPUT -v -n", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0a78a59755a5e572f0949991e8ac9435", "name": "4.4.3.1 — Ensure ip6tables default deny firewall policy", "description": "Ensure ip6tables default deny firewall policy", "rational": "With a default accept policy the firewall will accept any packet that is not configured to \nbe denied. It is easier to allow list acceptable usage than to deny list unacceptable \nusage. \n\nPage 508", "remediation": "- IF - IPv6 is enabled on your system: \nRun the following commands to implement a default DROP policy: \n\n# ip6tables -P INPUT DROP \n# ip6tables -P OUTPUT DROP \n# ip6tables -P FORWARD DROP", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "ip6tables -L", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "52719a4c0080a227b895cc1f1fab77eb", "name": "5.1.4 — Ensure sshd access is configured", "description": "Ensure sshd access is configured", "rational": "Restricting which users can remotely access the system via SSH will help ensure that \nonly authorized users access the system. \n\nPage 534", "remediation": "Edit the /etc/ssh/sshd_config file to set one or more of the parameters above any \nInclude and Match set statements as follows: \n\nAllowUsers \n - AND/OR - \nAllowGroups \n\nNote: \n\n• First occurrence of a option takes precedence, Match set statements \n\nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a .conf file in an \nInclude directory. \n\n• Be advised that these options are \"AND...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -Pi -- '^\\h*(allow|deny)(users|groups)\\h+\\H+'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6855d7bad4af9e458791a0159e211aca", "name": "5.1.5 — Ensure sshd Banner is configured", "description": "Ensure sshd Banner is configured", "rational": "Banners are used to warn connecting users of the particular site's policy regarding \nconnection. Presenting a warning message prior to the normal user login may assist the \nprosecution of trespassers on the computer system. \n\nPage 537", "remediation": "Edit the /etc/ssh/sshd_config file to set the Banner parameter above any Include \nand Match entries as follows: \n\nBanner /etc/issue.net \n\nNote: First occurrence of a option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location. \nEdit the file being called by the Banner argument with the appropriate contents \naccording to your site policy, r...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -Pi -- '^banner\\h+\\/\\H+'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "3a8d700ca8a9996cd6642edbf8f368cd", "name": "5.1.6 — Ensure sshd Ciphers are configured", "description": "Ensure sshd Ciphers are configured", "rational": "Weak ciphers that are used for authentication to the cryptographic module cannot be \nrelied upon to provide confidentiality or integrity, and system data may be compromised. \n\n• The Triple DES ciphers, as used in SSH, have a birthday bound of approximately \nfour billion blocks, which makes it easier for remote attackers to obtain clear text \ndata via a birthday attack against a long-duration e...", "remediation": "Edit the /etc/ssh/sshd_config file and add/modify the Ciphers line to contain a comma \nseparated list of the site unapproved (weak) Ciphers preceded with a - above any \nInclude entries: \nExample: \n\nCiphers -3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc,chacha20-\npoly1305@openssh.com \n\n- IF - CVE-2023-48795 has been addressed, and it meets local site policy, chacha20-\npoly1305@openssh.com may be removed from the list of excluded ciphers. \nNote: First occurrence of an option takes precedence. If In...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -Pi --", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "3c031f47dac4ec124027c73900b77d6a", "name": "5.1.9 — Ensure sshd GSSAPIAuthentication is disabled", "description": "Ensure sshd GSSAPIAuthentication is disabled", "rational": "Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote \nhosts, and should be disabled to reduce the attack surface of the system", "remediation": "Edit the /etc/ssh/sshd_config file to set the GSSAPIAuthentication parameter to \nno above any Include and Match entries as follows: \n\nGSSAPIAuthentication no \n\nNote: First occurrence of an option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location. \n\nPage 549", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep gssapiauthentication", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "644da87f154c6b6cac82babdef96900b", "name": "5.1.11 — Ensure sshd IgnoreRhosts is enabled", "description": "Ensure sshd IgnoreRhosts is enabled", "rational": "Setting this parameter forces users to enter a password when authenticating with SSH.", "remediation": "Edit the /etc/ssh/sshd_config file to set the IgnoreRhosts parameter to yes above \nany Include and Match entries as follows: \n\nIgnoreRhosts yes \n\nNote: First occurrence of a option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep ignorerhosts", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "b294f80727d220ddeda19316fefa7ec6", "name": "5.1.12 — Ensure sshd KexAlgorithms is configured", "description": "Ensure sshd KexAlgorithms is configured", "rational": "Key exchange methods that are considered weak should be removed. A key exchange \nmethod may be weak because too few bits are used, or the hashing algorithm is \nconsidered too weak. Using weak algorithms could expose connections to man-in-the-\nmiddle attacks \n\nPage 555", "remediation": "Edit the /etc/ssh/sshd_config file and add/modify the KexAlgorithms line to contain \na comma separated list of the site unapproved (weak) KexAlgorithms preceded with a - \nabove any Include entries: \nExample: \n\nKexAlgorithms -diffie-hellman-group1-sha1,diffie-hellman-group14-sha1,diffie-\nhellman-group-exchange-sha1 \n\nNote: First occurrence of an option takes precedence. If Include locations are enabled, \nused, and order of precedence is understood in your environment, the entry may be \ncreated...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -Pi -- 'kexalgorithms\\h+([^#\\n\\r]+,)?(diffie-hellman-group1-", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "b2f93989191fc67466d122e2a0638f88", "name": "5.1.13 — Ensure sshd LoginGraceTime is configured", "description": "Ensure sshd LoginGraceTime is configured", "rational": "Setting the LoginGraceTime parameter to a low number will minimize the risk of \nsuccessful brute force attacks to the SSH server. It will also limit the number of \nconcurrent unauthenticated connections While the recommended setting is 60 seconds \n(1 Minute), set the number based on site policy.", "remediation": "Edit the /etc/ssh/sshd_config file to set the LoginGraceTime parameter to 60 \nseconds or less above any Include entry as follows: \n\nLoginGraceTime 60 \n\nNote: First occurrence of a option takes precedence. If Include locations are enabled, \nused, and order of precedence is understood in your environment, the entry may be \ncreated in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep logingracetime", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1c43cdba8617eb4a03a0601e3f3ff649", "name": "5.1.14 — Ensure sshd LogLevel is configured", "description": "Ensure sshd LogLevel is configured", "rational": "The INFO level is the basic level that only records login activity of SSH users. In many \nsituations, such as Incident Response, it is important to determine when a particular \nuser was active on a system. The logout record can eliminate those users who \ndisconnected, which helps narrow the field. \n\nThe VERBOSE level specifies that login and logout activity as well as the key fingerprint \nfor a...", "remediation": "Edit the /etc/ssh/sshd_config file to set the LogLevel parameter to VERBOSE or \nINFO above any Include and Match entries as follows: \n\nLogLevel VERBOSE \n - OR - \nLogLevel INFO \n\nNote: First occurrence of an option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep loglevel", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "4125e3fdcab10832c49b79e27fe43878", "name": "5.1.15 — Ensure sshd MACs are configured", "description": "Ensure sshd MACs are configured", "rational": "MD5 and 96-bit MAC algorithms are considered weak and have been shown to increase \nexploitability in SSH downgrade attacks. Weak algorithms continue to have a great deal \nof attention as a weak spot that can be exploited with expanded computing power. An \nattacker that breaks the algorithm could take advantage of a MiTM position to decrypt \nthe SSH tunnel and capture credentials and information...", "remediation": "Edit the /etc/ssh/sshd_config file and add/modify the MACs line to contain a comma \nseparated list of the site unapproved (weak) MACs preceded with a - above any \nInclude entries: \nExample: \n\nMACs -hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-sha1-96,umac-\n64@openssh.com,hmac-md5-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac-\nripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,umac-64-\netm@openssh.com,umac-128-etm@openssh.com \n\n- IF - CVE-2023-48795 has not been reviewed and addressed, the...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -Pi -- 'macs\\h+([^#\\n\\r]+,)?(hmac-md5|hmac-md5-96|hmac-", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9e06983135654bbb0c0da0355320ef9d", "name": "5.1.16 — Ensure sshd MaxAuthTries is configured", "description": "Ensure sshd MaxAuthTries is configured", "rational": "Setting the MaxAuthTries parameter to a low number will minimize the risk of \nsuccessful brute force attacks to the SSH server. While the recommended setting is 4, \nset the number based on site policy.", "remediation": "Edit the /etc/ssh/sshd_config file to set the MaxAuthTries parameter to 4 or less \nabove any Include and Match entries as follows: \n\nMaxAuthTries 4 \n\nNote: First occurrence of an option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location. \n\nPage 565", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep maxauthtries", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "d0b814286b4856dac8fac2b83c5ae4e2", "name": "5.1.17 — Ensure sshd MaxSessions is configured", "description": "Ensure sshd MaxSessions is configured", "rational": "To protect a system from denial of service due to a large number of concurrent \nsessions, use the rate limiting function of MaxSessions to protect availability of sshd \nlogins and prevent overwhelming the daemon.", "remediation": "Edit the /etc/ssh/sshd_config file to set the MaxSessions parameter to 10 or less \nabove any Include and Match entries as follows: \n\nMaxSessions 10 \n\nNote: First occurrence of an option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -i maxsessions", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "cde3ea8e2614db757dd154c7fe269d15", "name": "5.1.18 — Ensure sshd MaxStartups is configured", "description": "Ensure sshd MaxStartups is configured", "rational": "To protect a system from denial of service due to a large number of pending \nauthentication connection attempts, use the rate limiting function of MaxStartups to \nprotect availability of sshd logins and prevent overwhelming the daemon.", "remediation": "Edit the /etc/ssh/sshd_config file to set the MaxStartups parameter to 10:30:60 or \nmore restrictive above any Include entries as follows: \n\nMaxStartups 10:30:60 \n\nNote: First occurrence of a option takes precedence. If Include locations are enabled, \nused, and order of precedence is understood in your environment, the entry may be \ncreated in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | awk '$1 ~ /^\\s*maxstartups/{split($2, a, \":\");{if(a[1] > 10 ||", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1d772dd912eb6d07c81ced8b256eedc2", "name": "5.1.20 — Ensure sshd PermitRootLogin is disabled", "description": "Ensure sshd PermitRootLogin is disabled", "rational": "Disallowing root logins over SSH requires system admins to authenticate using their \nown individual account, then escalating to root. This limits opportunity for non-\nrepudiation and provides a clear audit trail in the event of a security incident.", "remediation": "Edit the /etc/ssh/sshd_config file to set the PermitRootLogin parameter to no \nabove any Include and Match entries as follows: \n\nPermitRootLogin no \n\nNote: First occurrence of an option takes precedence, Match set statements \nwithstanding. If Include locations are enabled, used, and order of precedence is \nunderstood in your environment, the entry may be created in a file in Include location. \n\nPage 573", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep permitrootlogin", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e30d818a8f74edbf364c1876cd45c6bb", "name": "5.1.22 — Ensure sshd UsePAM is enabled", "description": "Ensure sshd UsePAM is enabled", "rational": "When usePAM is set to yes, PAM runs through account and session types properly. This \nis important if you want to restrict access to services based off of IP, time or other \nfactors of the account. Additionally, you can make sure users inherit certain \nenvironment variables on login or disallow access to the server", "remediation": "Edit the /etc/ssh/sshd_config file to set the UsePAM parameter to yes above any \nInclude entries as follows: \n\nUsePAM yes \n\nNote: First occurrence of an option takes precedence. If Include locations are enabled, \nused, and order of precedence is understood in your environment, the entry may be \ncreated in a file in Include location.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "sshd -T | grep -i usepam", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "09af5c5d0f06814129ae430177e9a266", "name": "5.2.1 — Ensure sudo is installed", "description": "Ensure sudo is installed", "rational": "sudo supports a plug-in architecture for security policies and input/output logging. Third \nparties can develop and distribute their own policy and I/O logging plug-ins to work \nseamlessly with the sudo front end. The default security policy is sudoers, which is \nconfigured via the file /etc/sudoers and any entries in /etc/sudoers.d. \n\nThe security policy determines what privileges, if any, a u...", "remediation": "First determine if LDAP functionality is required. If so, then install sudo-ldap, else \ninstall sudo. \nExample: \n\n# apt install sudo \n\nPage 580", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "sudo", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "bb135b4ac693cd333719fa6fcdff877f", "name": "5.2.2 — Ensure sudo commands use pty", "description": "Ensure sudo commands use pty", "rational": "Attackers can run a malicious program using sudo which would fork a background \nprocess that remains even when the main program has finished executing.", "remediation": "Edit the file /etc/sudoers with visudo or a file in /etc/sudoers.d/ with visudo -f \n and add the following line: \n\nDefaults use_pty \n\nEdit the file /etc/sudoers with visudo and any files in /etc/sudoers.d/ with visudo \n-f and remove any occurrence of !use_pty \nNote: \n\n• sudo will read each file in /etc/sudoers.d, skipping file names that end in ~ or \ncontain a . character to avoid causing problems with package manager or editor \ntemporary/backup files. \n\n• Files...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -rPi -- '^\\h*Defaults\\h+([^#\\n\\r]+,\\h*)?use_pty\\b' /etc/sudoers*", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "125ff57a907a467bca05d65f3b3e24f5", "name": "5.2.3 — Ensure sudo log file exists", "description": "Ensure sudo log file exists", "rational": "A sudo log file simplifies auditing of sudo commands", "remediation": "Edit the file /etc/sudoers or a file in /etc/sudoers.d/ with visudo or visudo -f \n and add the following line: \nExample: \n\nDefaults logfile=\"/var/log/sudo.log\" \n\nNote: \n\n• sudo will read each file in /etc/sudoers.d, skipping file names that end in ~ or \ncontain a . character to avoid causing problems with package manager or editor \ntemporary/backup files. \n\n• Files are parsed in sorted lexical order. That is, /etc/sudoers.d/01_first will \n\nbe parsed before /etc/sudoers.d/10_se...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -rPsi", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1b1a456b61d81ca76ebee78ebacef1f7", "name": "5.2.7 — Ensure access to the su command is restricted", "description": "Ensure access to the su command is restricted", "rational": "Restricting the use of su , and using sudo in its place, provides system administrators \nbetter control of the escalation of user privileges to execute privileged commands. The \nsudo utility also provides a better logging and audit mechanism, as it can log each \ncommand executed via sudo , whereas su can only record that a user executed the su \nprogram.", "remediation": "Create an empty group that will be specified for use of the su command. The group \nshould be named according to site policy. \nExample: \n\n# groupadd sugroup \n\nAdd the following line to the /etc/pam.d/su file, specifying the empty group: \n\nauth required pam_wheel.so use_uid group=sugroup", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "FILE", "input": "/etc/group", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0ccf956dc367a8a5023cdf127ce1542d", "name": "5.3.1.1 — Ensure latest version of pam is installed", "description": "Ensure latest version of pam is installed", "rational": "To ensure the system has full functionality and access to the options covered by this \nBenchmark the latest version of libpam-runtime should be installed on the system", "remediation": "- IF - the version of libpam-runtime on the system is less than version 1.5.3-5: \nRun the following command to update to the latest version of PAM: \n\n# apt upgrade libpam-runtime \n\nPage 598", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "libpam-runtime", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "400ce3ee1d3db96c5f10bf38f07b97aa", "name": "5.3.1.2 — Ensure libpam-modules is installed", "description": "Ensure libpam-modules is installed", "rational": "To ensure the system has full functionality and access to the PAM options covered by \nthis Benchmark", "remediation": "- IF - the version of libpam-modules on the system is less than version 1.5.3-5: \nRun the following command to update to the latest version of PAM: \n\n# apt upgrade libpam-modules \n\nPage 599", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "libpam-modules", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "4f8aa64dab8ea54503ba2aac43f10e32", "name": "5.3.1.3 — Ensure libpam-pwquality is installed", "description": "Ensure libpam-pwquality is installed", "rational": "Strong passwords reduce the risk of systems being hacked through brute force \nmethods.", "remediation": "Run the following command to install libpam-pwquality: \n\n# apt install libpam-pwquality", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "libpam-pwquality", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9463b34ea996111778e08c303e034bc1", "name": "5.3.2.1 — Ensure pam_unix module is enabled", "description": "Ensure pam_unix module is enabled", "rational": "The system should only provide access after performing authentication of a user.", "remediation": "Run the following command to enable the pam_unix module: \n\n# pam-auth-update --enable unix \n\nNote: If a site specific custom profile is being used in your environment to configure \nPAM that includes the configuration for the pam_faillock module, enable that module \ninstead", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -P -- '\\bpam_unix\\.so\\b' /etc/pam.d/common-", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "6da35c04bfbdc85e79903ab6fbe68e8d", "name": "5.3.2.2 — Ensure pam_faillock module is enabled", "description": "Ensure pam_faillock module is enabled", "rational": "Locking out user IDs after n unsuccessful consecutive login attempts mitigates brute \nforce password attacks against your systems.", "remediation": "Create two pam-auth-update profiles in /usr/share/pam-configs/: \n\n1. Create the faillock profile in /usr/share/pam-configs/ with the following \n\nlines: \n\nName: Enable pam_faillock to deny access \nDefault: yes \nPriority: 0 \nAuth-Type: Primary \nAuth: \n [default=die] pam_faillock.so authfail \n\nExample Script: \n\n#!/usr/bin/env bash \n\n{ \n arr=('Name: Enable pam_faillock to deny access' 'Default: yes' 'Priority: \n0' 'Auth-Type: Primary' 'Auth:' ' [default=die]...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -P -- '\\bpam_faillock\\.so\\b' /etc/pam.d/common-{auth,account}", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "73ebe0b68f2466c322d7374075e3f88f", "name": "5.3.2.3 — Ensure pam_pwquality module is enabled", "description": "Ensure pam_pwquality module is enabled", "rational": "Use of a unique, complex passwords helps to increase the time and resources required \nto compromise the password.", "remediation": "Run the following script to verify the pam_pwquality.so line exists in a pam-auth-\nupdate profile: \n\n# grep -P -- '\\bpam_pwquality\\.so\\b' /usr/share/pam-configs/* \n\nOutput should be similar to: \n\nPage 607 \n\n\f/usr/share/pam-configs/pwquality: requisite \npam_pwquality.so retry=3 \n/usr/share/pam-configs/pwquality: requisite \npam_pwquality.so retry=3 \n\n- IF - similar output is returned: \nRun the following command to update /etc/pam.d/common-...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -P -- '\\bpam_pwquality\\.so\\b' /etc/pam.d/common-password", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9a1850a45f65270b4a6416a0fbaf887b", "name": "5.3.2.4 — Ensure pam_pwhistory module is enabled", "description": "Ensure pam_pwhistory module is enabled", "rational": "Use of a unique, complex passwords helps to increase the time and resources required \nto compromise the password.", "remediation": "Run the following script to verify the pam_pwquality.so line exists in a pam-auth-\nupdate profile: \n\n# grep -P -- '\\bpam_pwhistory\\.so\\b' /usr/share/pam-configs/* \n\nOutput should be similar to: \n\n/usr/share/pam-configs/pwhistory: requisite pam_pwhistory.so remember=24 \nenforce_for_root try_first_pass use_authtok \n\n- IF - similar output is returned: \nRun the following command to update /etc/pam.d/common-password with the \nreturned profile: \n\n# pam-auth-update --enable {PROFILE_NAME} \n\nExam...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -P -- '\\bpam_pwhistory\\.so\\b' /etc/pam.d/common-password", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e030d02d2016dc6ae16f9bf92269ff61", "name": "5.3.3.1.2 — Ensure password unlock time is configured", "description": "Ensure password unlock time is configured", "rational": "Locking out user IDs after n unsuccessful consecutive login attempts mitigates brute \nforce password attacks against your systems.", "remediation": "Set password unlock time to conform to site policy. unlock_time should be 0 (never), \nor 900 seconds or greater. \nEdit /etc/security/faillock.conf and update or add the following line: \n\nunlock_time = 900 \n\nRun the following command: remove the unlock_time argument from the \npam_faillock.so module in the PAM files: \n\n# grep -Pl -- '\\bpam_faillock\\.so\\h+([^#\\n\\r]+\\h+)?unlock_time\\b' \n/usr/share/pam-configs/* \n\nEdit any returned files and remove the unlock_time= argument from the \npam_faillo...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -Pi -- '^\\h*unlock_time\\h*=\\h*(0|9[0-9][0-9]|[1-9][0-9]{3,})\\b'", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9331f0ec4ace305bc357d6e6aec9e204", "name": "5.3.3.4.1 — Ensure pam_unix does not include nullok", "description": "Ensure pam_unix does not include nullok", "rational": "Using a strong password is essential to helping protect personal and sensitive \ninformation from unauthorized access", "remediation": "Run the following command: \n\n# grep -PH -- '^\\h*([^#\\n\\r]+\\h+)?pam_unix\\.so\\h+([^#\\n\\r]+\\h+)?nullok\\b' \n/usr/share/pam-configs/* \n\nEdit any files returned and remove the nullok argument for the pam_unix lines \nExample File: \n\nName: Unix authentication \nDefault: yes \nPriority: 256 \nAuth-Type: Primary \nAuth: \n [success=end default=ignore] pam_unix.so try_first_pass # <- \n**ensure line does not include nullok nullok** \nAuth-Initial: \n [success=end default=ignore] pam_unix.so...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -PH -- '^\\h*^\\h*[^#\\n\\r]+\\h+pam_unix\\.so\\b' /etc/pam.d/common-", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1dbbec3f74370e64e27c2cde27c8d218", "name": "5.3.3.4.4 — Ensure pam_unix includes use_authtok", "description": "Ensure pam_unix includes use_authtok", "rational": "use_authtok allows multiple pam modules to confirm a new password before it is \naccepted.", "remediation": "Run the following command: \n\n# awk '/Password-Type:/{ f = 1;next } /-Type:/{ f = 0 } f {if \n(/pam_unix\\.so/) print FILENAME}' /usr/share/pam-configs/* \n\nEdit any returned files add use_authtok to the pam_unix line in the Password section \nunder Password: subsection: \nNote: The if the file's Password section includes a Password-Initial: subsection, \nuse_authtok should not be added to the pam_unix line in the Password-Initial: \nsubsection \nExample File: \n\nName: Unix authentication \nDefault: yes...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -PH --", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "dc0b86d74d9a6acf1aea21952f61d379", "name": "5.4.1.1 — Ensure password expiration is configured", "description": "Ensure password expiration is configured", "rational": "The window of opportunity for an attacker to leverage compromised credentials or \nsuccessfully compromise credentials via an online brute force attack is limited by the \nage of the password. Therefore, reducing the maximum age of a password also reduces \nan attacker's window of opportunity. \n\nWe recommend a yearly password change. This is primarily because for all their good \nintentions users w...", "remediation": "Set the PASS_MAX_DAYS parameter to conform to site policy in /etc/login.defs : \n\nPASS_MAX_DAYS 365 \n\nModify user parameters for all users with a password set to match: \n\n# chage --maxdays 365 \n\nEdit /etc/login.defs and set PASS_MAX_DAYS to a value greater than 0 that follows \nlocal site policy: \nExample: \n\nPASS_MAX_DAYS 365 \n\nRun the following command to modify user parameters for all users with a password set \nto a maximum age no greater than 365 or less than 1 that follows local site...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -Pi -- '^\\h*PASS_MAX_DAYS\\h+\\d+\\b' /etc/login.defs", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "965bc000eb400c0ddc1f21622638cdc8", "name": "5.4.1.5 — Ensure inactive password lock is configured", "description": "Ensure inactive password lock is configured", "rational": "Inactive accounts pose a threat to system security since the users are not logging in to \nnotice failed login attempts or other anomalies.", "remediation": "Run the following command to set the default password inactivity period to 45 days or \nless that meets local site policy: \n\n# useradd -D -f \n\nExample: \n\n# useradd -D -f 45 \n\nRun the following command to modify user parameters for all users with a password set \nto a inactive age of 45 days or less that follows local site policy: \n\n# chage --inactive \n\nExample: \n\n# awk -F: '($2~/^\\$.+\\$/) {if($7 > 45 || $7 < 0)system (\"chage --inactive 45 \n\" $1)}' /etc/shadow", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "useradd -D | grep INACTIVE", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "ee17e3cc23efaf08f34cea544153d26a", "name": "5.4.2.1 — Ensure root is the only UID 0 account", "description": "Ensure root is the only UID 0 account", "rational": "This access must be limited to only the default root account and only from the system \nconsole. Administrative access must be through an unprivileged account using an \napproved mechanism as noted in Item 5.6 Ensure access to the su command is \nrestricted.", "remediation": "Run the following command to change the root account UID to 0: \n\n# usermod -u 0 root \n\nModify any users other than root with UID 0 and assign them a new UID.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "awk -F: '($3 == 0) { print $1 }' /etc/passwd", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "0a77f53a42d7b57fa8bf8ddbe5698626", "name": "5.4.2.2 — Ensure root is the only GID 0 account", "description": "Ensure root is the only GID 0 account", "rational": "Using GID 0 for the root account helps prevent root -owned files from accidentally \nbecoming accessible to non-privileged users.", "remediation": "Run the following command to set the root user's GID to 0: \n\n# usermod -g 0 root \n\nRun the following command to set the root group's GID to 0: \n\n# groupmod -g 0 root \n\nRemove any users other than the root user with GID 0 or assign them a new GID if \nappropriate.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "awk -F: '($1 !~ /^(sync|shutdown|halt|operator)/ && $4==\"0\") {print", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1f3d8c59da2ea9098fc664fd464e0763", "name": "5.4.2.3 — Ensure group root is the only GID 0 group", "description": "Ensure group root is the only GID 0 group", "rational": "Using GID 0 for the root group helps prevent root group owned files from accidentally \nbecoming accessible to non-privileged users.", "remediation": "Run the following command to set the root group's GID to 0: \n\n# groupmod -g 0 root \n\nRemove any groups other than the root group with GID 0 or assign them a new GID if \nappropriate.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "awk -F: '$3==\"0\"{print $1\":\"$3}' /etc/group", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "5d32f0f933a2b61e7f85fd741541c54d", "name": "5.4.2.4 — Ensure root account access is controlled", "description": "Ensure root account access is controlled", "rational": "Access to root should be secured at all times.", "remediation": "Run the following command to set a password for the root user: \n\n# passwd root \n\n- OR - \nRun the following command to lock the root user account: \n\n# usermod -L root", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "passwd -S root | awk '$2 ~ /^(P|L)/ {print \"User: \\\"\" $1 \"\\\" Password is", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "cd346aa468029c2675635e21fd528a48", "name": "5.4.2.5 — Ensure root path integrity", "description": "Ensure root path integrity", "rational": "Including the current working directory (.) or other writable directory in root's \nexecutable path makes it likely that an attacker can gain superuser access by forcing an \nadministrator operating as root to execute a Trojan horse program. \n\nPage 702", "remediation": "Correct or justify any: \n\n• Locations that are not directories \n• Empty directories (::) \n• Trailing (:) \n• Current working directory (.) \n• Non root owned directories \n• Directories that less restrictive than mode 0755", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "8d2582df2c1574e00bb68e14e59aaa29", "name": "5.4.2.6 — Ensure root user umask is configured", "description": "Ensure root user umask is configured", "rational": "Setting a secure value for umask ensures that users make a conscious choice about \ntheir file permissions. A permissive umask value could result in directories or files with \nexcessive permissions that can be read and/or written to by unauthorized users.", "remediation": "Edit /root/.bash_profile and /root/.bashrc and remove, comment out, or update \nany line with umask to be 0027 or more restrictive.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "grep -Psi -- '^\\h*umask\\h+(([0-7][0-7][01][0-7]\\b|[0-7][0-7][0-7][0-", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "1a088cbbbffe11d5b98c3d129514f35a", "name": "5.4.3.1 — Ensure nologin is not listed in /etc/shells", "description": "Ensure nologin is not listed in /etc/shells", "rational": "A user can use chsh to change their configured shell. \n\nIf a user has a shell configured that isn't in in /etc/shells, then the system assumes \nthat they're somehow restricted. In the case of chsh it means that the user cannot \nchange that value. \n\nOther programs might query that list and apply similar restrictions. \n\nBy putting nologin in /etc/shells, any user that has nologin as its shell is...", "remediation": "Edit /etc/shells and remove any lines that include nologin", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "FILE", "input": "/etc/shells", "selement": "CONTENT", "condition": "NOT CONTAINS", "sinput": "^\\h*([^#\\n\\r]+)?\\/nologin\\b" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c01bd8f62c3b45f5e89ae67f4e785b2f", "name": "5.4.3.3 — Ensure default user umask is configured", "description": "Ensure default user umask is configured", "rational": "Setting a secure default value for umask ensures that users make a conscious choice \nabout their file permissions. A permissive umask value could result in directories or files \nwith excessive permissions that can be read and/or written to by unauthorized users. \n\nPage 721", "remediation": "Run the following script and perform the instructions in the output to set the default \numask to 027 or more restrictive: \n\n#!/usr/bin/env bash \n\n{ \n l_output=\"\" l_output2=\"\" l_out=\"\" \n file_umask_chk() \n { \n if grep -Psiq -- '^\\h*umask\\h+(0?[0-7][2-\n7]7|u(=[rwx]{0,3}),g=([rx]{0,2}),o=)(\\h*#.*)?$' \"$l_file\"; then \n l_out=\"$l_out\\n - umask is set correctly in \\\"$l_file\\\"\" \n elif grep -Psiq -- '^\\h*umask\\h+(([0-7][0-7][01][0-7]\\b|[0-7][0-7][0-\n7][0-6]\\b)|([0-7][01][0-7]\\...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "54e4648b140eb870b7d2795e8a73c51b", "name": "6.1.1.1 — Ensure journald service is enabled and active", "description": "Ensure journald service is enabled and active", "rational": "If the systemd-journald service is not enabled to start on boot, the system will not \ncapture logging events.", "remediation": "Run the following commands to unmask and start systemd-journald.service \n\n# systemctl unmask systemd-journald.service \n# systemctl start systemd-journald.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "systemd-journald", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "c15316f46a65a4bc17ad4e0c5b4f936f", "name": "6.1.1.4 — Ensure only one logging system is in use", "description": "Ensure only one logging system is in use", "rational": "Configuring only one logging service either rsyslog - OR - journald avoids \nredundancy, optimizes resources, simplifies configuration and management, and \nensures consistency.", "remediation": "1. Determine whether to use journald - OR - rsyslog depending on site needs \n2. Configure systemd-jounald.service \n3. Configure only ONE either journald - OR - rsyslog and complete the \n\nrecommendations in that subsection \n\n4. Return to this recommendation to ensure only one logging system is in use \n\nPage 739 \n\n \n \n \n\f6.1.2 Configure journald \n\nIncluded in the systemd suite is a journaling service called systemd-journald.service for \nthe collection and storage of logging data. It creates...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "--quiet", "selement": "ACTIVE", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "474149f13e134b662e9a0950d24746fa", "name": "6.1.2.1.1 — Ensure systemd-journal-remote is installed", "description": "Ensure systemd-journal-remote is installed", "rational": "Storing log data on a remote host protects log integrity from local attacks. If an attacker \ngains root access on the local system, they could tamper with or remove log data that is \nstored on the local system. \n\nNote: This recommendation only applies if journald is the chosen method for \nclient side logging. Do not apply this recommendation if rsyslog is used.", "remediation": "Run the following command to install systemd-journal-remote: \n\n# apt install systemd-journal-remote", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "systemd-journal-remote", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "f68204dbff1ff3bc448a3e2247b6137f", "name": "6.1.2.2 — Ensure journald ForwardToSyslog is disabled", "description": "Ensure journald ForwardToSyslog is disabled", "rational": "- IF - journald is the method for capturing logs, all logs of the system should be \nhandled by journald and not forwarded to other logging mechanisms. \n\nNote: This recommendation only applies if journald is the chosen method for \nclient side logging. Do not apply this recommendation if rsyslog is used.", "remediation": "- IF - rsyslog is the preferred method for capturing logs, this section and \nRecommendation should be skipped and the \"Configure rsyslog\" section followed. \n- IF - journald is the preferred method for capturing logs: \nSet the following parameter in the [Journal] section in \n/etc/systemd/journald.conf or a file in /etc/systemd/journald.conf.d/ ending in \n.conf: \n\nForwardToSyslog=no \n\nExample script to create systemd drop-in configuration file: \n\n#!/usr/bin/env bash \n\n{ \n a_settings=(\"Forward...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "9ef887774b625dc85efc6031932b27a8", "name": "6.1.2.3 — Ensure journald Compress is configured", "description": "Ensure journald Compress is configured", "rational": "Uncompressed large files may unexpectedly fill a filesystem leading to resource \nunavailability. Compressing logs prior to write can prevent sudden, unexpected \nfilesystem impacts. \n\nNote: This recommendation only applies if journald is the chosen method for \nclient side logging. Do not apply this recommendation if rsyslog is used.", "remediation": "- IF - rsyslog is the preferred method for capturing logs, this section and \nRecommendation should be skipped and the \"Configure rsyslog\" section followed. \n- IF - journald is the preferred method for capturing logs: \nSet the following parameter in the [Journal] section in \n/etc/systemd/journald.conf or a file in /etc/systemd/journald.conf.d/ ending \nin .conf: \n\nCompress=yes \n\nExample script to create systemd drop-in configuration file: \n\n#!/usr/bin/env bash \n\n{ \n a_settings=(\"Compress=yes\"...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "42d818e8e27c8afb426c1ebaec829fb5", "name": "6.1.2.4 — Ensure journald Storage is configured", "description": "Ensure journald Storage is configured", "rational": "Writing log data to disk will provide the ability to forensically reconstruct events which \nmay have impacted the operations or security of a system even after a system crash or \nreboot. \n\nNote: This recommendation only applies if journald is the chosen method for \nclient side logging. Do not apply this recommendation if rsyslog is used.", "remediation": "- IF - rsyslog is the preferred method for capturing logs, this section and \nRecommendation should be skipped and the \"Configure rsyslog\" section followed. \n- IF - journald is the preferred method for capturing logs: \nSet the following parameter in the [Journal] section in \n/etc/systemd/journald.conf or a file in /etc/systemd/journald.conf.d/ ending in \n.conf: \n\nStorage=persistent \n\nExample script to create systemd drop-in configuration file: \n\n#!/usr/bin/env bash \n\n{ \n a_settings=(\"Storage...", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "f493152191ea1e7c9af1e40fa4d8ccd8", "name": "6.1.3.1 — Ensure rsyslog is installed", "description": "Ensure rsyslog is installed", "rational": "The security enhancements of rsyslog such as connection-oriented (i.e. TCP) \ntransmission of logs, the option to log to database formats, and the encryption of log \ndata en route to a central logging server) justify installing and configuring the package.", "remediation": "Run the following command to install rsyslog: \n\n# apt install rsyslog", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "rsyslog", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "103d06b7b7dcc5da987db4d455991508", "name": "6.1.3.2 — Ensure rsyslog service is enabled and active", "description": "Ensure rsyslog service is enabled and active", "rational": "If the rsyslog service is not enabled to start on boot, the system will not capture \nlogging events.", "remediation": "- IF - rsyslog is being used for logging on the system: \nRun the following commands to unmask, enable, and start rsyslog.service: \n\n# systemctl unmask rsyslog.service \n# systemctl enable rsyslog.service \n# systemctl start rsyslog.service", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "rsyslog", "selement": "ENABLED", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e8ee55ef31a99afdbc2f13b7e9682946", "name": "6.3.1 — Ensure AIDE is installed", "description": "Ensure AIDE is installed", "rational": "By monitoring the filesystem state compromised files can be detected to prevent or limit \nthe exposure of accidental or malicious misconfigurations or modified binaries.", "remediation": "Install AIDE using the appropriate package manager or manual installation: \n\n# apt install aide aide-common \n\nConfigure AIDE as appropriate for your environment. Consult the AIDE documentation \nfor options. \nRun the following commands to initialize AIDE: \n\n# aideinit \n# mv /var/lib/aide/aide.db.new /var/lib/aide/aide.db", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "PACKAGE", "input": "aide", "selement": "EXISTS", "condition": "", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "a67e42ba1a291d675646156c3da07a03", "name": "6.3.2 — Ensure filesystem integrity is regularly checked", "description": "Ensure filesystem integrity is regularly checked", "rational": "Periodic file checking allows the system administrator to determine on a regular basis if \ncritical files have been changed in an unauthorized fashion.", "remediation": "Run the following command to unmask dailyaidecheck.timer and \ndailyaidecheck.service: \n\n# systemctl unmask dailyaidecheck.timer dailyaidecheck.service \n\nRun the following command to enable and start dailyaidecheck.timer: \n\n# systemctl --now enable dailyaidecheck.timer", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "SERVICE", "input": "dailyaidecheck.timer", "selement": "ACTIVE", "condition": null, "sinput": null } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "94202ee5af80ad1faad0c651b76fe2ad", "name": "7.2.4 — Ensure shadow group is empty", "description": "Ensure shadow group is empty", "rational": "Any users assigned to the shadow group would be granted read access to the \n/etc/shadow file. If attackers can gain read access to the /etc/shadow file, they can \neasily run a password cracking program against the hashed passwords to break them. \nOther security information that is stored in the /etc/shadow file (such as expiration) \ncould also be useful to subvert additional user accounts.", "remediation": "Run the following command to remove all users from the shadow group \n\n# sed -ri 's/(^shadow:[^:]*:[^:]*:)([^:]+$)/\\1/' /etc/group \n\nChange the primary group of any users with shadow as their primary group. \n\n# usermod -g ", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "awk -F: '($1==\"shadow\") {print $NF}' /etc/group", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "b5b420a506ac1a93b0817f8ae8bc87ce", "name": "7.2.5 — Ensure no duplicate UIDs exist", "description": "Ensure no duplicate UIDs exist", "rational": "Users must be assigned unique UIDs for accountability and to ensure appropriate \naccess protections.", "remediation": "Based on the results of the audit script, establish unique UIDs and review all files owned \nby the shared UIDs to determine which UID they are supposed to belong to.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "bd42a53d530b2180a22450bbb4f6a773", "name": "7.2.6 — Ensure no duplicate GIDs exist", "description": "Ensure no duplicate GIDs exist", "rational": "User groups must be assigned unique GIDs for accountability and to ensure appropriate \naccess protections.", "remediation": "Based on the results of the audit script, establish unique GIDs and review all files \nowned by the shared GID to determine which group they are supposed to belong to.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "2680d02566dac78398901622ea573a1d", "name": "7.2.7 — Ensure no duplicate user names exist", "description": "Ensure no duplicate user names exist", "rational": "If a user is assigned a duplicate user name, it will create and have access to files with \nthe first UID for that username in /etc/passwd . For example, if \"test4\" has a UID of \n1000 and a subsequent \"test4\" entry has a UID of 2000, logging in as \"test4\" will use \nUID 1000. Effectively, the UID is shared, which is a security problem.", "remediation": "Based on the results of the audit script, establish unique user names for the users. File \nownerships will automatically reflect the change as long as the users have unique UIDs.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] }, { "external_id": "e66ad8bce08a44f878458fd856efaf16", "name": "7.2.8 — Ensure no duplicate group names exist", "description": "Ensure no duplicate group names exist", "rational": "If a group is assigned a duplicate group name, it will create and have access to files \nwith the first GID for that group in /etc/group . Effectively, the GID is shared, which is \na security problem.", "remediation": "Based on the results of the audit script, establish unique names for the user groups. File \ngroup ownerships will automatically reflect the change as long as the groups have \nunique GIDs.", "severity": "Medium", "filter": null, "app_filter": null, "conditions": [ { "type": "condition", "element": "CMD", "input": "!/usr/bin/env bash", "selement": "OUTPUT", "condition": "NOT EQUALS", "sinput": "" } ], "applicability": [ { "type": "applicability", "element": "OS", "input": "", "selement": "CONTENT", "condition": "CONTAINS", "sinput": "Ubuntu" } ] } ] }