cis-ubuntu1204-v110-9-1-2

name	cis-ubuntu1204-v110-9-1-2
description	Set User/Group Owner and Permission on /etc/crontab
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","authentication","cron","permissions"]
cis_id	9.1.2
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

9.1.2 Set User/Group Owner and Permission on /etc/crontab (Scored)

Profile Applicability

• Level 1

Description

The /etc/crontab file is used by cron to control its own jobs. The commands in this item make sure that root is the user and group owner of the file and that only the owner can access the file.

Rationale

This file contains information on what system jobs are run by cron. Write access to these files could provide unprivileged users with the ability to elevate their privileges. Read access to these files could provide users with the ability to gain insight on system jobs that run on the system and could provide them a way to gain unauthorized privileged access.

Audit Procedure

Using Command Line

Perform the following to determine if the /etc/crontab file has the correct permissions:

stat -c "%a %u %g" /etc/crontab | egrep ".00 0 0"

Expected Result

If the above command emits no output then the system is not configured as recommended. Expected output should match the pattern .00 0 0 (owner root, group root, permissions restrictive).

Remediation

Using Command Line

chown root:root /etc/crontab
chmod og-rwx /etc/crontab

Default Value

The default permissions on /etc/crontab may vary by installation.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 1 - Scored