Cis Ubuntu1404 V210 5 3 3

---
name: "CIS Ubuntu 14.04 LTS - 5.3.3 Ensure password reuse is limited"
description: "Verify PAM is configured to remember at least 5 previous passwords to prevent reuse"
category: "cis-os-hardening"
version: "2.1.0"
author: "cyberstrike-official"
tags:
  - cis
  - ubuntu
  - ubuntu-14.04
  - level-1
  - scored
  - pam
cis_id: "5.3.3"
cis_benchmark: "CIS Ubuntu Linux 14.04 LTS Benchmark v2.1.0"
tech_stack:
  - ubuntu
  - linux
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: "medium"
---

# 5.3.3 Ensure password reuse is limited (Scored)

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

The `/etc/security/opasswd` file stores the users' old passwords and can be checked to ensure that users are not recycling recent passwords.

## Rationale

Forcing users not to reuse their past 5 passwords make it less likely that an attacker will be able to guess the password.

Note that these change only apply to accounts configured on the local system.

## Audit Procedure

Run the following commands and ensure the `remember` option is '5' or more and included in all results:

```bash
egrep '^password\s+required\s+pam_pwhistory.so' /etc/pam.d/common-password
```

## Expected Result

```
password required pam_pwhistory.so remember=5
```

## Remediation

Edit the `/etc/pam.d/common-password` file to include the `remember` option and conform to site policy as shown:

```
password required pam_pwhistory.so remember=5
```

## Default Value

No password reuse limit configured by default.

## References

- CIS Controls: 16 - Account Monitoring and Control

## Profile

- Level 1 - Server
- Level 1 - Workstation