# CIS Ubuntu 14.04 LTS - 6.1.7 Ensure permissions on /etc/shadow- are configured

> Verify /etc/shadow- has correct ownership and permissions (640 or more restrictive)

- Skill: `cyberstrikeus/cis-ubuntu-14-04-lts-6-1-7-ensure-permissions-on-etc-shadow-` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu-14-04-lts-6-1-7-ensure-permissions-on-etc-shadow-`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu-14-04-lts-6-1-7-ensure-permissions-on-etc-shadow-/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-ubuntu-14-04-lts-6-1-7-ensure-permissions-on-etc-shadow-

---


# 6.1.7 Ensure permissions on /etc/shadow- are configured (Scored)

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

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

## Rationale

It is critical to ensure that the `/etc/shadow-` file is protected from unauthorized access. Although it is protected by default, the file permissions could be changed either inadvertently or through malicious actions.

## Audit Procedure

Run the following command and verify `Uid` is `0/root`, `Gid` is `0/root` or `<gid>/shadow`, and `Access` is `640` or more restrictive:

```bash
stat /etc/shadow-
```

## Expected Result

```
Access: (0640/-rw-r-----)  Uid: (    0/    root)   Gid: (   42/  shadow)
```

## Remediation

Run the one of the following chown commands as appropriate and the chmod to set permissions on `/etc/shadow-`:

```bash
chown root:root /etc/shadow-
chown root:shadow /etc/shadow-

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

## Default Value

Access: (0640/-rw-r-----) Uid: ( 0/ root) Gid: ( 42/ shadow)

## References

None

## CIS Controls

16.14 Encrypt/Hash All Authentication Files And Monitor Their Access - Verify that all authentication files are encrypted or hashed and that these files cannot be accessed without root or administrator privileges. Audit all access to password files in the system.

## Profile

- Level 1