cis-ubuntu1204-v110-13-20

name	cis-ubuntu1204-v110-13-20
description	Check for Presence of User .forward Files
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","user-management","forward","email","mail-forwarding"]
cis_id	13.20
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

13.20 Check for Presence of User .forward Files (Scored)

Profile Applicability

• Level 1

Description

The .forward file specifies an email address to forward the user's mail to.

Rationale

Use of the .forward file poses a security risk in that sensitive data may be inadvertently transferred outside the organization. The .forward file also poses a risk as it can be used to execute commands that may perform unintended actions.

Audit Procedure

Using Command Line

This script checks for the presence of .forward files that may be in violation of the site security policy.

#!/bin/bash
for dir in `/bin/cat /etc/passwd |\
/usr/bin/awk -F: '{ print $6 }'`; do
    if [ ! -h "$dir/.forward" -a -f "$dir/.forward" ]; then
echo ".forward file $dir/.forward exists"
    fi
done

Expected Result

No output should be returned. Any output indicates the presence of .forward files in user home directories.

Remediation

Using Command Line

Making global modifications to users' files without alerting the user community can result in unexpected outages and unhappy users. Therefore, it is recommended that a monitoring policy be established to report user .forward files and determine the action to be taken in accordance with site policy.

Default Value

No .forward files exist by default on Ubuntu 12.04.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored