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cis-ubuntu1804-v220-4-2-1

DevOps & Security
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Ensure permissions on /etc/ssh/sshd_config are configured

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How to use this skill

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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_18.04_LTS_Benchmark_v2.2.0/cis-ubuntu1804-v220-4-2-1/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-ubuntu1804-v220-4-2-1/. Do not write files or run scripts until I approve.

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

CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 - Control 4.2.1

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Description

The /etc/ssh/sshd_config file contains configuration specifications for sshd. The command below sets the owner and group of the file to root.

Rationale

The /etc/ssh/sshd_config file needs to be protected from unauthorized changes by non-privileged users.

Audit Procedure

Command Line

Run the following command and verify Uid and Gid are both 0/root and Access does not grant permissions to group or other:

stat -c "%a %U %G" /etc/ssh/sshd_config

Expected Result

600 root root

OR more restrictive.

Remediation

Command Line

Run the following commands to set ownership and permissions on /etc/ssh/sshd_config:

chown root:root /etc/ssh/sshd_config
chmod og-rwx /etc/ssh/sshd_config

Default Value

Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/ root)

References

  1. NIST SP 800-53 Rev. 5: AC-3, MP-2

CIS Controls

v8 - 3.3 Configure Data Access Control Lists - Configure data access control lists based on a user's need to know. Apply data access control lists, also known as access permissions, to local and remote file systems, databases, and applications.

v7 - 14.6 Protect Information through Access Control Lists - Protect all information stored on systems with file system, network share, claims, application, or database specific access control lists.

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Assessment Status

Automated