cis-ubuntu1604-v200-5-5-3

name	cis-ubuntu1604-v200-5-5-3
description	Ensure default group for the root account is GID 0
category	cis-iam
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","authentication","pam"]
cis_id	5.5.3
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

Ensure default group for the root account is GID 0

Profile Applicability:

• Level 1 - Server
• Level 1 - Workstation

Assessment Status: Automated

Description

The usermod command can be used to specify which group the root user belongs to. This affects permissions of files that are created by the root user.

Rationale

Using GID 0 for the root account helps prevent root-owned files from accidentally becoming accessible to non-privileged users.

Audit Procedure

Command Line

Run the following command and verify the result is 0:

grep "^root:" /etc/passwd | cut -f4 -d:

Expected output:

0

Remediation

Command Line

Run the following command to set the root user default group to GID 0:

usermod -g 0 root

References

None

CIS Controls

Controls Version	Control
v7	14.6 Protect Information through Access Control Lists - Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists. These controls will enforce the principle that only authorized individuals should have access to the information based on their need to access the information as a part of their responsibilities.

Profile

• Level 1 - Server
• Level 1 - Workstation