# Cis Ubuntu1804 V220 4 3 6

> Ensure sudo authentication timeout is configured correctly

- Skill: `cyberstrikeus/cis-ubuntu1804-v220-4-3-6` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1804-v220-4-3-6`
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- Category: Coding & Dev Tools
- Author: cyberstrikeus (https://skillmd.com/u/cyberstrikeus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/cyberstrikeus/cis-ubuntu1804-v220-4-3-6

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# CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.3.6

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

`sudo` caches credentials for a period of time. The default timeout for the `sudo` command is 15 minutes. It is recommended that the timeout be set to no more than 15 minutes.

## Rationale

If the timeout is too long, a user could execute commands as root for an extended period without re-authenticating. This could allow unauthorized users to execute commands as root if the original user walks away from their terminal.

## Audit Procedure

### Command Line

Run the following command to verify the sudo authentication timeout:

```bash
grep -roP "timestamp_timeout\h*=\h*\d+" /etc/sudoers /etc/sudoers.d/
```

### Expected Result

If output is returned, `timestamp_timeout` should be 15 or less. If no output is returned, the default of 15 minutes is in effect, which is compliant.

## Remediation

### Command Line

Edit the file `/etc/sudoers` or a file in `/etc/sudoers.d/` with `visudo` and set or modify the `timestamp_timeout` value:

```bash
Defaults timestamp_timeout=15
```

OR set to a value of 15 or less per site policy.

## Default Value

timestamp_timeout=15

## References

1. NIST SP 800-53 Rev. 5: IA-11

## CIS Controls

v8 - 5.4 Restrict Administrator Privileges to Dedicated Administrator Accounts.

v7 - 4.3 Ensure the Use of Dedicated Administrative Accounts.

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Assessment Status

Automated