# Cis GCP Cos 1.1.6

> Ensure nosuid option set on /var partition

- Skill: `cyberstrikeus/cis-gcp-cos-1-1-6` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-gcp-cos-1-1-6`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-gcp-cos-1-1-6/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-gcp-cos-1-1-6

---


# 1.1.6 Ensure nosuid option set on /var partition (Automated)

## Description

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

## Rationale

Since the `/var` filesystem is only intended for temporary dynamic data, set this option to ensure that users cannot create `setuid` files in `/var`.

## Audit Procedure

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

```bash
# mount | grep -E '\s/var\s' | grep -v nosuid
```

## Expected Result

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

## Remediation

Run the following command to remount `/var`:

```bash
# mount -o remount,nosuid /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               | 3.3 Configure Data Access Control Lists - Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications. | x    | x    | x    |
| v7               | 5.1 Establish Secure Configurations - Maintain documented, standard security configuration standards for all authorized operating systems and software.                                                                                         | x    | x    | x    |

## Profile

Level 2 - Server | Automated