# yaml-language-server: $schema=../../../../schema/control.schema.json
id: CB-DEB-AUDIT-031
title: Restrict access to the audit configuration and tools
finding:
  title: Audit configuration or tools can be changed by users other than root
  description: Whoever can change the audit rules, the daemon settings or the audit programs can blind or fool the audit system.
status: active
profiles: [server-hardened, desktop-hardened]
risk:
  severity: medium
assessment: automated
tags: [auditd, permissions]

description: |
  - The configuration files `/etc/audit/*.conf`, `/etc/audit/*.rules`,
    `/etc/audit/rules.d/*.rules` and `/etc/audit/plugins.d/*.conf` must be owned by root:root with
    mode `0640` or stricter.
  - The audit tools `auditctl`, `auditd`, `augenrules`, `aureport`, `ausearch` and `autrace` in
    `/usr/sbin/` must be owned by root:root with mode `0755` or stricter.
rationale: |
  Writable rules or settings let a user disable auditing; a writable tool can be replaced by one
  that hides records. Readable rules tell an attacker what is watched.
impact: |
  None known. Debian installs these files with these permissions.
notes: |
  `autrace` is no longer shipped by auditd 4 (Debian 13); its check is then not applicable.

setting:
  location: /etc/audit/, /usr/sbin/au*
  default_value: Configuration root:root 0640, tools root:root 0755
  recommended_value: Configuration root:root 0640 or stricter, tools root:root 0755 or stricter

audit:
  manual: |
    1. Run `stat -c '%n %U:%G %a' /etc/audit/*.conf /etc/audit/*.rules /etc/audit/rules.d/*.rules /etc/audit/plugins.d/*.conf`.
       Each file must be root:root with mode 0640 or stricter.
    2. Run `stat -c '%n %U:%G %a' /usr/sbin/auditctl /usr/sbin/auditd /usr/sbin/augenrules /usr/sbin/aureport /usr/sbin/ausearch /usr/sbin/autrace`.
       Each file must be root:root with mode 0755 or stricter.
  checks:
    - id: conf
      engine: file-perms
      description: Owner, group and mode of /etc/audit/*.conf.
      spec: { path: "/etc/audit/*.conf", owner: root, group: root, mode: "0640" }
    - id: rules
      engine: file-perms
      description: Owner, group and mode of /etc/audit/*.rules.
      spec: { path: "/etc/audit/*.rules", owner: root, group: root, mode: "0640" }
    - id: rules-d
      engine: file-perms
      description: Owner, group and mode of /etc/audit/rules.d/*.rules.
      spec: { path: "/etc/audit/rules.d/*.rules", owner: root, group: root, mode: "0640" }
    - id: plugins-d
      engine: file-perms
      description: Owner, group and mode of /etc/audit/plugins.d/*.conf.
      spec: { path: "/etc/audit/plugins.d/*.conf", owner: root, group: root, mode: "0640" }
    - id: auditctl
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/auditctl.
      spec: { path: /usr/sbin/auditctl, owner: root, group: root, mode: "0755" }
    - id: auditd
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/auditd.
      spec: { path: /usr/sbin/auditd, owner: root, group: root, mode: "0755" }
    - id: augenrules
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/augenrules.
      spec: { path: /usr/sbin/augenrules, owner: root, group: root, mode: "0755" }
    - id: aureport
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/aureport.
      spec: { path: /usr/sbin/aureport, owner: root, group: root, mode: "0755" }
    - id: ausearch
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/ausearch.
      spec: { path: /usr/sbin/ausearch, owner: root, group: root, mode: "0755" }
    - id: autrace
      engine: file-perms
      description: Owner, group and mode of /usr/sbin/autrace.
      spec: { path: /usr/sbin/autrace, owner: root, group: root, mode: "0755" }

remediation:
  manual: |
    Run `chown root:root` and `chmod 640` on the configuration files, and `chown root:root` and
    `chmod 755` on the tools.
  effects:
    restart: none
    disruption: none
    lockout_risk: false
  rollback: |
    No rollback needed; these are the Debian defaults.
  scripts:
    - id: conf
      from_check: conf
    - id: rules
      from_check: rules
    - id: rules-d
      from_check: rules-d
    - id: plugins-d
      from_check: plugins-d
    - id: auditctl
      from_check: auditctl
    - id: auditd
      from_check: auditd
    - id: augenrules
      from_check: augenrules
    - id: aureport
      from_check: aureport
    - id: ausearch
      from_check: ausearch
    - id: autrace
      from_check: autrace

references:
  - title: auditctl(8), Debian manual pages
    url: https://manpages.debian.org/trixie/auditd/auditctl.8.en.html
    publisher: Debian
    kind: vendor-doc
    accessed: 2026-10-18
  - title: auditd.conf(5), Debian manual pages
    url: https://manpages.debian.org/trixie/auditd/auditd.conf.5.en.html
    publisher: Debian
    kind: vendor-doc
    accessed: 2026-10-18
mappings:
  - framework: anssi-linux
    framework_version: "2.0"
    id: R73
    relation: related
  - framework: nist-800-53r5
    framework_version: "5.1.1"
    id: AU-9
    relation: related
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.5"
    relation: equivalent
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.6"
    relation: equivalent
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.7"
    relation: equivalent
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.8"
    relation: equivalent
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.9"
    relation: equivalent
  - framework: cis-debian-12
    framework_version: "2.0.0"
    id: "6.2.4.10"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.5"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.6"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.7"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.8"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.9"
    relation: equivalent
  - framework: cis-debian-13
    framework_version: "1.1.0"
    id: "6.2.4.10"
    relation: equivalent
threats:
  - framework: mitre-attack
    id: T1562.012
  - framework: cwe
    id: CWE-732
related_controls:
  - id: CB-DEB-AUDIT-011
    type: requires

authors:
  - name: Alice
    github: Sn0wAlice
verified:
  - date: 2026-10-18
    by: Sn0wAlice
    versions: ["12"]
    environment: Proxmox VM, Debian 12 genericcloud image, kernel 6.1.0-54-cloud-amd64, BIOS boot
    notes: "Not applicable before auditd; passes after install; kept after reboot."
  - date: 2026-10-18
    by: Sn0wAlice
    versions: ["13"]
    environment: Proxmox VM, Debian 13 genericcloud image, kernel 6.12.113+deb13-cloud-amd64, BIOS boot
    notes: "Not applicable before auditd; passes after install; autrace absent in auditd 4 (check not applicable)."
introduced_in: 0.1.0
created: 2026-10-18
updated: 2026-10-18