# Cis Ubuntu1804 V220 5 2 4 5

> 5.2.4.5 Ensure audit configuration files are 640 or more restrictive

- Skill: `cyberstrikeus/cis-ubuntu1804-v220-5-2-4-5` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1804-v220-5-2-4-5`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1804-v220-5-2-4-5/raw
- Safety review: CAUTION (external: skill-scanner FAIL, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu1804-v220-5-2-4-5

---


# 5.2.4.5 Ensure audit configuration files are 640 or more restrictive

## Description

Audit configuration files control auditd and what events are audited.

## Rationale

Access to the audit configuration files could allow unauthorized personnel to prevent the auditing of critical events.

Misconfigured audit configuration files may prevent the auditing of critical events or impact the system's performance by overwhelming the audit log. Misconfiguration of the audit configuration files may also make it more difficult to establish and investigate events relating to an incident.

## Audit

Run the following command to verify that the audit configuration files have mode 640 or more restrictive and are owned by the root user and root group:

```bash
find /etc/audit/ -type f \( -name '*.conf' -o -name '*.rules' \) -exec stat -Lc "%n %a" {} + | grep -Pv -- '^\h*\H+\h+([0,2,4,6][0,4]0)\h*$'
```

**Expected result:** Nothing should be returned

## Remediation

Run the following command to remove more permissive mode than 0640 from the audit configuration files:

```bash
find /etc/audit/ -type f \( -name '*.conf' -o -name '*.rules' \) -exec chmod u=rw,g=r,o= {} +
```

## References

1. NIST SP 800-53 Rev. 5: AU-3

## Metadata

- **Profile Applicability:** Level 2 - Server, Level 2 - Workstation
- **Category:** cis-logging
- **Tags:** cis, ubuntu, linux, ubuntu-18.04, auditing, auditd
- **Version:** 2.2.0
- **Severity Boost:** {}
- **Automated:** Yes
- **CIS Controls:**
  - v8: 3.3 Configure Data Access Control Lists
  - v7: 14.6 Protect Information through Access Control Lists
- **MITRE ATT&CK:**
  - Tactics: TA0007 (Discovery)
  - Techniques: T1070, T1070.002, T1083, T1083.000
  - Mitigations: M1047 (Audit)