# CIS Ubuntu 14.04 LTS - 5.4.5 Ensure default user shell timeout is 900 seconds or less

> Verify TMOUT is set to 900 seconds or less in shell configuration files for idle session timeout

- Skill: `cyberstrikeus/cis-ubuntu-14-04-lts-5-4-5-ensure-default-user-shell-timeout` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu-14-04-lts-5-4-5-ensure-default-user-shell-timeout`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu-14-04-lts-5-4-5-ensure-default-user-shell-timeout/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-ubuntu-14-04-lts-5-4-5-ensure-default-user-shell-timeout

---


# 5.4.5 Ensure default user shell timeout is 900 seconds or less (Scored)

## Profile Applicability

- Level 2 - Server
- Level 2 - Workstation

## Description

The default `TMOUT` determines the shell timeout for users. The TMOUT value is measured in seconds.

## Rationale

Having no timeout value associated with a shell could allow an unauthorized user access to another user's shell session (e.g. user walks away from their computer and doesn't lock the screen). Setting a timeout value at least reduces the risk of this happening.

## Audit Procedure

Run the following commands and verify all TMOUT lines returned are 900 or less and at least one exists in each file:

```bash
grep "^TMOUT" /etc/bashrc
grep "^TMOUT" /etc/profile
```

## Expected Result

```
TMOUT=600
```

## Remediation

Edit the `/etc/bashrc` and `/etc/profile` files (and the appropriate files for any other shell supported on your system) and add or edit any umask parameters as follows:

```
TMOUT=600
```

## Default Value

No TMOUT configured by default.

## References

- CIS Controls: 16.4 - Automatically Log Off Users After Standard Period Of Inactivity

## Profile

- Level 2 - Server
- Level 2 - Workstation