cis-gcp-cos-1-1-13

name	cis-gcp-cos-1.1.13
description	Disable Automounting
category	cis-gcp-cos
version	1.2.0
author	cyberstrike-official
tags	["cis","gcp","container-optimized-os","filesystem","partitions","mount-options","automounting"]
cis_id	1.1.13
cis_benchmark	CIS Google Container-Optimized OS Benchmark v1.2.0
tech_stack	["gcp","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

1.1.13 Disable Automounting (Automated)

Description

autofs allows automatic mounting of devices, typically including CD/DVDs and USB drives.

Rationale

With automounting enabled anyone with physical access could attach a USB drive or disc and have its contents available in system even if they lacked permissions to mount it themselves.

Impact

The use of portable hard drives is very common for workstation users. If your organization allows the use of portable storage or media on workstations and physical access controls to workstations is considered adequate there is little value add in turning off automounting.

Audit Procedure

Run the following command and verify result is not "enabled":

# systemctl is-enabled autofs
disabled

Expected Result

The command should return disabled (not enabled).

Remediation

Run the following command to disable autofs:

# systemctl disable autofs

Default Value

Additional methods of disabling a service exist. Consult your distribution documentation for appropriate methods.

This control should align with the tolerance of the use of portable drives and optical media in the organization. On a server requiring an admin to manually mount media can be part of defense-in-depth to reduce the risk of unapproved software or information being introduced or proprietary software or information being exfiltrated. If admins commonly use flash drives and Server access has sufficient physical controls, requiring manual mounting may not increase security.

Profile

Level 1 - Server | Automated