cis-ubuntu1604-v200-1-1-8

name	cis-ubuntu1604-v200-1-1-8
description	Ensure nosuid option set on /dev/shm partition
category	cis-storage
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","filesystem","dev-shm","nosuid","mount-option"]
cis_id	1.1.8
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

Ensure nosuid option set on /dev/shm partition

Description

The nosuid mount option specifies that the filesystem cannot contain setuid files.

Rationale

Setting this option on a file system prevents users from introducing privileged programs onto the system and allowing non-root users to execute them.

Impact

None noted.

Audit Procedure

Command Line

# Run the following command and verify that nothing is returned:
findnmt -n /dev/shm | grep -v nosuid

Expected Result

No output should be returned.

Remediation

Command Line

# Edit the /etc/fstab file and add nosuid to the fourth field (mounting options) for the /dev/shm partition.
# See the fstab(5) manual page for more information.
# Run the following command to remount /dev/shm:
mount -o remount,nosuid,nodev,noexec /dev/shm

Default Value

Not set by default.

References

• CIS Controls Version 7 - 5.1 Establish Secure Configurations: Maintain documented, standard security configuration standards for all authorized operating systems and software.

Profile

Level 1 - Server / Level 1 - Workstation, Assessment: Automated