cis-ubuntu2004-v300-6-2-3-4

DevOps & Security

Ensure rsyslog log file creation mode is configured

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_20.04_LTS_Benchmark_v3.0.0/cis-ubuntu2004-v300-6-2-3-4/SKILL.md

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6.2.3.4 Ensure rsyslog log file creation mode is configured (Automated)

Profile

Level 1 - Server
Level 1 - Workstation

Description

The $FileCreateMode parameter allows to specify the creation mode with which rsyslogd creates new files.

Rationale

It is important to ensure that log files have the correct permissions to ensure that sensitive data is archived and protected.

Audit Procedure

Command Line

Run the following command to verify $FileCreateMode to set to mode 0640 or more restrictive:

# grep ^\$FileCreateMode /etc/rsyslog.conf /etc/rsyslog.d/*.conf

Expected Result

$FileCreateMode 0640

Should a site policy dictate less restrictive permissions, ensure to follow said policy. Note: More restrictive permissions such as 0600 is implicitly sufficient.

Remediation

Command Line

Edit either /etc/rsyslog.conf or a dedicated .conf file in /etc/rsyslog.d/ and set $FileCreateMode to 0640 or more restrictive:

$FileCreateMode 0640

Reload the service:

# systemctl reload-or-restart rsyslog

Default Value

Not specifically configured by default.

References

RSYSLOG.CONF(5)
NIST SP 800-53 Rev. 5: AC-3, AC-6, MP-2
https://www.rsyslog.com/doc/configuration/action/rsconf1_filecreatemode.html

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.3 Configure Data Access Control Lists
v8	8.2 Collect Audit Logs
v7	5.1 Establish Secure Configurations
v7	6.2 Activate audit logging
v7	6.3 Enable Detailed Logging

MITRE ATT&CK Mappings

Techniques / Sub-techniques	Tactics	Mitigations
T1070, T1070.002, T1083, T1083.000	TA0007	M1022