cis-gcp-cos-5-3-1-3

name	cis-gcp-cos-5.3.1.3
description	Ensure password expiration warning days is 7 or more
category	cis-gcp-cos
version	1.2.0
author	cyberstrike-official
tags	["cis","gcp","container-optimized-os","shadow","password-expiration","user-accounts"]
cis_id	5.3.1.3
cis_benchmark	CIS Google Container-Optimized OS Benchmark v1.2.0
tech_stack	["gcp","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

5.3.1.3 Ensure password expiration warning days is 7 or more (Automated)

Description

The PASS_WARN_AGE parameter in /etc/login.defs allows an administrator to notify users that their password will expire in a defined number of days. It is recommended that the PASS_WARN_AGE parameter be set to 7 or more days.

Rationale

Providing an advance warning that a password will be expiring gives users time to think of a secure password. Users caught unaware may choose a simple password or write it down where it may be discovered.

Audit Procedure

Run the following command and verify PASS_WARN_AGE conforms to site policy (No less than 7 days):

# grep PASS_WARN_AGE /etc/login.defs

PASS_WARN_AGE 7

Verify all users with a password have their number of days of warning before password expires set to 7 or more:

Run the following command and Review list of users and PASS_WARN_AGE to verify that all users' PASS_WARN_AGE conforms to site policy (No less than 7 days):

# grep -E '^[^:]+:[^\!*]' /etc/shadow | cut -d: -f1,6

<user>:<PASS_WARN_AGE>

Expected Result

PASS_WARN_AGE should be 7 or more in /etc/login.defs and for all users with a password in /etc/shadow.

Remediation

Set the PASS_WARN_AGE parameter to 7 in /etc/login.defs:

PASS_WARN_AGE 7

Modify user parameters for all users with a password set to match:

# chage --warndays 7 <user>

Additional Information:

You can also check this setting in /etc/shadow directly. The 6th field should be 7 or more for all users with a password.

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	5.2 Use Unique Passwords - Use unique passwords for all enterprise assets. Best practice implementation includes, at a minimum, an 8-character password for accounts using MFA and a 14-character password for accounts not using MFA.	x