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cis-ubuntu1804-v220-4-1-6

DevOps & Security
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Ensure permissions on /etc/cron.monthly are configured

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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-v220-4-1-6/SKILL.md

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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 4.1.6

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Description

The /etc/cron.monthly directory contains system cron jobs that need to run on a monthly basis. The files in this directory cannot be manipulated by the crontab command, but are instead edited by system administrators using a text editor. The commands below restrict read/write and search access to user and group root, preventing regular users from accessing this directory.

Rationale

Granting write access to this directory for non-privileged users could provide them the means for gaining unauthorized elevated privileges. Granting read access to this directory could give an unprivileged user insight in how to gain elevated privileges or circumvent auditing controls.

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/cron.monthly/

Expected Result

700 root root

OR more restrictive.

Remediation

Command Line

Run the following commands to set ownership and permissions on /etc/cron.monthly/:

chown root:root /etc/cron.monthly/
chmod og-rwx /etc/cron.monthly/

Default Value

Access: (0755/drwxr-xr-x) 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