# Cis Ubuntu1204 V110 12 2

> Verify Permissions on /etc/shadow

- Skill: `cyberstrikeus/cis-ubuntu1204-v110-12-2` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1204-v110-12-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1204-v110-12-2/raw
- Safety review: PASS (external: skill-scanner PASS, skillspector CAUTION)
- 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-ubuntu1204-v110-12-2

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# 12.2 Verify Permissions on /etc/shadow (Scored)

## Profile Applicability

- Level 1

## Description

The `/etc/shadow` file is used to store the information about user accounts that is critical to the security of those accounts, such as the hashed password and other security information.

## Rationale

If attackers can gain read access to the `/etc/shadow` file, they can easily run a password cracking program against the hashed password to break it. Other security information that is stored in the `/etc/shadow` file (such as expiration) could also be useful to subvert the user accounts.

## Audit Procedure

### Using Command Line

Run the following command to determine the permissions on the `/etc/shadow` file. Ensure world has no access, group has no write or execute access.

```bash
/bin/ls -l /etc/shadow
```

## Expected Result

```
-rw-r----- 1 root shadow <size> <date> shadow
```

Permissions should be `o-rwx,g-rw` or more restrictive.

## Remediation

### Using Command Line

If the permissions of the `/etc/shadow` file are incorrect, run the following commands to correct them:

```bash
/bin/chmod o-rwx,g-rw /etc/shadow
```

## Default Value

640 (rw-r-----)

## References

- CIS Ubuntu 12.04 LTS Server Benchmark v1.1.0

## Profile

Level 1 - Scored