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cis-ubuntu1604-v200-3-5-1-5

DevOps & Security
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Ensure ufw outbound connections are configured

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How to use this skill

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  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
Prompt to paste
I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_16.04_LTS_Benchmark_v2.0.0/cis-ubuntu1604-v200-3-5-1-5/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/cis-ubuntu1604-v200-3-5-1-5/. Do not write files or run scripts until I approve.

After I approve, install the complete skill folder, including required referenced files, into that project location. Verify it is discoverable, then tell me its actual invocation name and how to use it. Do not claim it is installed until you have verified it.

Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Control 3.5.1.5

Profile

  • Level: Level 1 - Server, Level 1 - Workstation
  • Assessment Status: Manual

Description

Configure the firewall rules for new outbound connections.

Notes:

  • Changing firewall settings while connected over network can result in being locked out of the system.
  • Unlike iptables, when a new outbound rule is added, ufw automatically takes care of associated established connections, so no rules for the latter kind are required.

Rationale

If rules are not in place for new outbound connections all packets will be dropped by the default policy preventing network usage.

Audit Procedure

Command Line

Run the following command and verify all rules for new outbound connections match site policy:

ufw status numbered

Remediation

Command Line

Configure ufw in accordance with site policy. The following commands will implement a policy to allow all outbound connections on all interfaces:

ufw allow out on all

References

None

CIS Controls

Version 7

9.4 Apply Host-based Firewalls or Port Filtering - Apply host-based firewalls or port filtering tools on end systems, with a default-deny rule that drops all traffic except those services and ports that are explicitly allowed.