cis-gcp-cos-6-1-4

name	cis-gcp-cos-6.1.4
description	Ensure permissions on /etc/gshadow are configured
category	cis-gcp-cos
version	1.2.0
author	cyberstrike-official
tags	["cis","gcp","container-optimized-os","file-permissions","gshadow","system-files"]
cis_id	6.1.4
cis_benchmark	CIS Google Container-Optimized OS Benchmark v1.2.0
tech_stack	["gcp","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

6.1.4 Ensure permissions on /etc/gshadow are configured (Automated)

Description

The /etc/gshadow file is used to store the information about groups that is critical to the security of those accounts, such as the hashed password and other security information.

Rationale

If attackers can gain read access to the /etc/gshadow file, they can easily run a password cracking program against the hashed password to break it. Other security information that is stored in the /etc/gshadow file (such as group administrators) could also be useful to subvert the group.

Audit Procedure

Run the following command and verify verify Uid is 0/root, Gid is 0/root or <gid>/shadow, and Access is 640 or more restrictive:

# stat /etc/gshadow
Access: (0640/-rw-r-----)  Uid: (    0/    root)   Gid: (    0/    root)

Expected Result

Uid should be 0/root, Gid should be 0/root or <gid>/shadow, and Access should be 640 or more restrictive.

Remediation

Run the one of the following chown commands as appropriate and the chmod to set permissions on /etc/gshadow:

# chown root:root /etc/gshadow
# chown root:shadow /etc/gshadow

# chmod o-rwx,g-rw /etc/gshadow

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	3.3 Configure Data Access Control Lists	x	x	x
v7	16.4 Encrypt or Hash all Authentication Credentials		x	x

Profile

• Level 1 - Server