# CIS Ubuntu 14.04 LTS - 1.4.3 Ensure authentication required for single user mode

> Verify that authentication is required when booting into single user mode

- Skill: `cyberstrikeus/cis-ubuntu-14-04-lts-1-4-3-ensure-authentication-required-fo` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu-14-04-lts-1-4-3-ensure-authentication-required-fo`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu-14-04-lts-1-4-3-ensure-authentication-required-fo/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-1-4-3-ensure-authentication-required-fo

---


# 1.4.3 Ensure authentication required for single user mode (Scored)

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

Single user mode is used for recovery when the system detects an issue during boot or by manual selection from the bootloader.

## Rationale

Requiring authentication in single user mode prevents an unauthorized user from rebooting the system into single user to gain root privileges without credentials.

## Audit Procedure

Perform the following to determine if a password is set for the root user:

```bash
grep ^root:[*\!]: /etc/shadow
```

No results should be returned.

## Expected Result

No output should be returned. If output is returned, the root account does not have a password set.

## Remediation

Run the following command and follow the prompts to set a password for the root user:

```bash
passwd root
```

## Default Value

Not applicable.

## References

- CIS Controls: 5.1 Minimize And Sparingly Use Administrative Privileges

## Profile

- Level 1 - Server
- Level 1 - Workstation