cis-ubuntu1204-v110-12-2

name	cis-ubuntu1204-v110-12-2
description	Verify Permissions on /etc/shadow
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","file-permissions","shadow","access-control","passwords"]
cis_id	12.2
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

12.2 Verify Permissions on /etc/shadow (Scored)

Profile Applicability

• Level 1

Description

The /etc/shadow file is used to store the information about user accounts 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/shadow 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/shadow file (such as expiration) could also be useful to subvert the user accounts.

Audit Procedure

Using Command Line

Run the following command to determine the permissions on the /etc/shadow file. Ensure world has no access, group has no write or execute access.

/bin/ls -l /etc/shadow

Expected Result

-rw-r----- 1 root shadow <size> <date> shadow

Permissions should be o-rwx,g-rw or more restrictive.

Remediation

Using Command Line

If the permissions of the /etc/shadow file are incorrect, run the following commands to correct them:

/bin/chmod o-rwx,g-rw /etc/shadow

Default Value

640 (rw-r-----)

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored