cis-ubuntu2004-v300-6-3-2-1

name	cis-ubuntu2004-v300-6-3-2-1
description	Ensure audit log storage size is configured
category	cis-logging
version	3.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-20.04","auditing","auditd"]
cis_id	6.3.2.1
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

6.3.2.1 Ensure audit log storage size is configured (Automated)

Profile

• Level 2 - Server
• Level 2 - Workstation

Description

Configure the maximum size of the audit log file. Once the log reaches the maximum size, it will be rotated and a new log file will be started.

Rationale

It is important that an appropriate size is determined for log files so that they do not impact the system and audit data is not lost.

Audit Procedure

Command Line

Run the following command and ensure output is in compliance with site policy:

# grep -Po -- '^\h*max_log_file\h*=\h*\d+\b' /etc/audit/auditd.conf
max_log_file = <MB>

Expected Result

The max_log_file parameter should be set in accordance with site policy.

Remediation

Command Line

Set the following parameter in /etc/audit/auditd.conf in accordance with site policy:

max_log_file = <MB>

Default Value

max_log_file = 8

References

1. NIST SP 800-53 Rev. 5: AU-8

Additional Information: The max_log_file parameter is measured in megabytes. Other methods of log rotation may be appropriate based on site policy. One example is time-based rotation strategies which don't have native support in auditd configurations. Manual audit of custom configurations should be evaluated for effectiveness and completeness.

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	8.3 Ensure Adequate Audit Log Storage	X	X	X
v7	6.4 Ensure adequate storage for logs		X	X

MITRE ATT&CK Mappings: T1562, T1562.006 / TA0040 / M1053