cis-ubuntu2004-v300-7-1-3

name	cis-ubuntu2004-v300-7-1-3
description	Ensure access to /etc/group is configured
category	cis-iam
version	3.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-20.04","file-permissions"]
cis_id	7.1.3
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

7.1.3 Ensure access to /etc/group is configured (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

The /etc/group file contains a list of all the valid groups defined in the system. The command below allows read/write access for root and read access for everyone else.

Rationale

The /etc/group file needs to be protected from unauthorized changes by non-privileged users, but needs to be readable as this information is used with many non-privileged programs.

Impact

None

Audit Procedure

Command Line

Run the following command to verify /etc/group is mode 644 or more restrictive, Uid is 0/root and Gid is 0/root:

# stat -Lc 'Access: (%#a/%A) Uid: ( %u/ %U) Gid: ( %g/ %G)' /etc/group

Expected Result

Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)

Remediation

Command Line

Run the following commands to remove excess permissions, set owner, and set group on /etc/group:

# chmod u-x,go-wx /etc/group
# chown root:root /etc/group

Default Value

Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)

References

1. NIST SP 800-53 Rev. 5: AC-3, MP-2

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.3 Configure Data Access Control Lists	X	X	X
v7	14.6 Protect Information through Access Control Lists	X	X	X

MITRE ATT&CK Mappings:

Techniques / Sub-techniques	Tactics	Mitigations
T1003, T1003.008, T1222, T1222.002	TA0005	M1022