# Cis Ubuntu2004 V300 4 2 3

> Ensure iptables-persistent is not installed with ufw

- Skill: `cyberstrikeus/cis-ubuntu2004-v300-4-2-3` (Agent Skill)
- Install (CLI): `npx skillmds@latest add cyberstrikeus/cis-ubuntu2004-v300-4-2-3`
- Raw SKILL.md: https://api.skillmd.com/api/skills/cyberstrikeus/cis-ubuntu2004-v300-4-2-3/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-ubuntu2004-v300-4-2-3

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# CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0 - Control 4.2.3

## Profile

- **Level:** Level 1 - Server, Level 1 - Workstation
- **Assessment Status:** Automated

## Description

The `iptables-persistent` is a boot-time loader for netfilter rules, iptables plugin

## Rationale

Running both `ufw` and the services included in the `iptables-persistent` package may lead to conflict

## Audit Procedure

### Command Line

Run the following command to verify that the `iptables-persistent` package is not installed:

```bash
dpkg-query -s iptables-persistent &>/dev/null && echo "iptables-persistent is installed"
```

## Expected Result

Nothing should be returned

## Remediation

### Command Line

Run the following command to remove the `iptables-persistent` package:

```bash
apt purge iptables-persistent
```

## Default Value

Not applicable.

## References

1. NIST SP 800-53 Rev. 5: SC-7

## CIS Controls

v8 - 4.4 Implement and Manage a Firewall on Servers
v8 - 4.5 Implement and Manage a Firewall on End-User Devices
v7 - 9.4 Apply Host-based Firewalls or Port Filtering

MITRE ATT&CK Mappings: T1562, T1562.004 | TA0005 | M1033