cis-gcp-cos-1.1.7

DevOps & Security

Ensure noexec option set on /var partition

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Cloud_Providers/Google_Cloud_Platform/CIS_Google_Container-Optimized_OS_Benchmark_v1.2.0/cis-gcp-cos-1.1.7/SKILL.md

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1.1.7 Ensure noexec option set on /var partition (Automated)

Description

The noexec mount option specifies that the filesystem cannot contain executable binaries.

Rationale

Since the /var filesystem is only intended for services to write data and not execute, set this option to ensure that users cannot run executable binaries from /var.

Audit Procedure

Verify that the noexec option is set if a /var partition exists. Run the following command and verify that nothing is returned:

# mount | grep -E '\s/var\s' | grep -v noexec

Expected Result

The command should return no output, confirming that the noexec option is set on the /var partition.

Remediation

Run the following command to remount /var:

# mount -o remount,noexec /var

Note: /etc is stateless on Container-Optimized OS. Therefore, /etc cannot be used to make these changes persistent across reboots. The steps mentioned above needs to be performed after every boot.

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	2.3 Address Unauthorized Software - Ensure that unauthorized software is either removed from use on enterprise assets or receives a documented exception. Review monthly, or more frequently.	x	x	x
v7	2.6 Address unapproved software - Ensure that unauthorized software is either removed or the inventory is updated in a timely manner.	x	x	x

Profile

Level 2 - Server | Automated