cis-ubuntu1204-v110-2-24

name	cis-ubuntu1204-v110-2-24
description	Disable Mounting of udf Filesystems
category	cis-os-hardening
version	1.1.0
author	cyberstrike-official
tags	["cis","ubuntu",12.04,"linux","filesystem","udf","kernel-module","attack-surface"]
cis_id	2.24
cis_benchmark	CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

2.24 Disable Mounting of udf Filesystems (Not Scored)

Profile Applicability

• Level 2

Description

The udf filesystem type is the universal disk format used to implement ISO/IEC 13346 and ECMA-167 specifications. This is an open vendor filesystem type for data storage on a broad range of media. This filesystem type is necessary to support writing DVDs and newer optical disc formats.

Rationale

Removing support for unneeded filesystem types reduces the local attack surface of the server. If this filesystem type is not needed, disable it.

Audit Procedure

Using Command Line

/sbin/modprobe -n -v udf
/sbin/lsmod | grep udf

Expected Result

The first command should output install /bin/true. The second command should produce no output (module not loaded).

Remediation

Using Command Line

Edit or create the file /etc/modprobe.d/CIS.conf and add the following line:

install udf /bin/true

Default Value

By default, the udf module is available for loading.

References

• CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

Profile

Level 2 - Not Scored