# Cis Ubuntu2004 V300 4 3 2

> Ensure ufw is uninstalled or disabled with nftables

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

---


# CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0 - Control 4.3.2

## Profile

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

## Description

Uncomplicated Firewall (UFW) is a program for managing a netfilter firewall designed to be easy to use.

## Rationale

Running both the `nftables` service and `ufw` may lead to conflict and unexpected results.

## Audit Procedure

### Command Line

Run the following commands to verify that `ufw` is either not installed or inactive. Only one of the following needs to pass.
Run the following command to verify that `ufw` is not installed:

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

Nothing should be returned
-OR-
Run the following commands to verify `ufw` is disabled and `ufw.service` is not enabled:

```bash
ufw status
```

```
Status: inactive
```

```bash
systemctl is-enabled ufw.service
```

```
masked
```

## Expected Result

ufw is not installed, or ufw status is inactive and ufw.service is masked.

## Remediation

### Command Line

Run one of the following to either remove `ufw` or disable `ufw` and mask `ufw.service`:
Run the following command to remove `ufw`:

```bash
apt purge ufw
```

-OR-
Run the following commands to disable `ufw` and mask `ufw.service`:

```bash
ufw disable
systemctl stop ufw.service
systemctl mask ufw.service
```

Note: `ufw disable` needs to be run before `systemctl mask ufw.service` in order to correctly disable UFW

## 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