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CIS Ubuntu 14.04 LTS - 5.1.2 Ensure permissions on /etc/crontab are configured

DevOps & Security
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Verify /etc/crontab ownership and permissions are restricted to root with no group/other access

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Source SKILL.md: https://github.com/CyberStrikeus/CyberStrike/blob/HEAD/.cyberstrike/skill/CIS_benchmarks/Operating_Systems/Ubuntu/CIS_Ubuntu_Linux_14.04_LTS_Benchmark_v2.1.0/cis-ubuntu1404-v210-5-1-2/SKILL.md

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5.1.2 Ensure permissions on /etc/crontab are configured (Scored)

Profile Applicability

  • Level 1 - Server
  • Level 1 - Workstation

Description

The /etc/crontab file is used by cron to control its own jobs. The commands in this item make sure that root is the user and group owner of the file and that only the owner can access the file.

Rationale

This file contains information on what system jobs are run by cron. Write access to these files could provide unprivileged users with the ability to elevate their privileges. Read access to these files could provide users with the ability to gain insight on system jobs that run on the system and could provide them a way to gain unauthorized privileged access.

Audit Procedure

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

stat /etc/crontab

Expected Result

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

Remediation

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

chown root:root /etc/crontab
chmod og-rwx /etc/crontab

Default Value

Not configured by default.

References

  • CIS Controls: 5.1 - Minimize And Sparingly Use Administrative Privileges

Profile

  • Level 1 - Server
  • Level 1 - Workstation