# Cis Ubuntu1604 V200 1 1 8

> Ensure nosuid option set on /dev/shm partition

- Skill: `cyberstrikeus/cis-ubuntu1604-v200-1-1-8` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1604-v200-1-1-8`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1604-v200-1-1-8/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu1604-v200-1-1-8

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# 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

```bash
# 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

```bash
# 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