# Cis Ubuntu1804 V220 4 5 1 4

> Ensure inactive password lock is 30 days or less

- Skill: `cyberstrikeus/cis-ubuntu1804-v220-4-5-1-4` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu1804-v220-4-5-1-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu1804-v220-4-5-1-4/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-ubuntu1804-v220-4-5-1-4

---


# CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.5.1.4

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Description

User accounts that have been inactive for an extended period of time pose a security risk. An attacker could use an inactive account to gain access to the system without being detected. It is recommended that inactive accounts be locked after 30 days.

## Rationale

Inactive accounts pose a threat to system security since the users are not logging in to notice failed login attempts or other anomalies.

## Audit Procedure

### Command Line

Run the following command and verify `INACTIVE` is 30 or less:

```bash
useradd -D | grep INACTIVE
```

Verify all users with a password have their inactive period set:

```bash
awk -F: '($2~/^\$.+\$/){print $1 " " $7}' /etc/shadow
```

### Expected Result

`INACTIVE=30` or less, but not `-1`.

No user should have a value greater than `30` or `-1` in field 7 of `/etc/shadow`.

## Remediation

### Command Line

Set the default inactive period:

```bash
useradd -D -f 30
```

Modify user parameters for all users with a password set to match:

```bash
chage --inactive 30 <user>
```

## Default Value

INACTIVE=-1

## References

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

## CIS Controls

v8 - 5.2 Use Unique Passwords - Use unique passwords for all enterprise assets.

v7 - 4.4 Use Unique Passwords.

## Profile Applicability

- Level 1 - Server
- Level 1 - Workstation

## Assessment Status

Automated