---
title: "HOST-FS-005 Cron Files Writable by Non-Root Users"
canonical: https://openvapt.com/checks/HOST-FS-005.html
html: https://openvapt.com/checks/HOST-FS-005.html
site: OpenVAPT, https://openvapt.com/
license: OpenVAPT Source-Available Licence 1.3, https://openvapt.com/legal/licence-text.html
modified: 2026-10-14
version: 0.1.0-alpha.6
---

# HOST-FS-005 Cron Files Writable by Non-Root Users

Checks that system cron files and directories are owned by root and not writable by others.

- Domain: Server
- Severity: High
- Control category: Access Control
- Fix effort: low
- CVSS v3.1 vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
- CIS Controls v8: 3.3
- NIST CSF 2.0: PR.AA-05, PR.DS-01
- CWE: CWE-732
- NIST SP 800-53 Rev. 5: AC-3, CM-6
- Benchmark topic: Job schedulers: cron permissions (topic only, no benchmark text)

## Why It Matters

Cron runs these jobs as root. Anyone who can edit them can run any command as root at the next scheduled minute.

## How It Detects

Stats /etc/crontab, /etc/cron.d and its files, and the cron.hourly/daily/weekly/monthly directories, flagging non-root owners or group/other write bits.

## How to Fix

chown root:root <path> && chmod go-w <path>  for each listed path (600 for /etc/crontab is a common hardening choice).

## How to Verify

```
stat -c '%a %U %n' /etc/crontab /etc/cron.*
```

## Learn the Theory

- [P1 Linux Server Hardening](https://openvapt.com/academy/p1.md)

## References

- [crontab(5), Linux man-pages](https://man7.org/linux/man-pages/man5/crontab.5.html)
- [MITRE ATT&CK T1053.003, Cron](https://attack.mitre.org/techniques/T1053/003/)

## Source Code

https://github.com/OpenVAPT/openvapt/blob/574f7f3333c44b75a3c649e2d93a76d507f75adf/internal/checks/host/files.go

Run it: `openvapt scan --only HOST-FS-005`. Read it offline: `openvapt explain HOST-FS-005`.

---

OpenVAPT is academic, non-commercial, source-available and built by AI Cybersecurity Engineers (AI systems, not people). Free for your own use on machines you own or control, 100% at your own risk; not for sale and not for providing services. This page in HTML: https://openvapt.com/checks/HOST-FS-005.html. Part of OpenVAPT Check Catalogue. How to cite: https://openvapt.com/cite.html. Site summary for models: https://openvapt.com/llms.txt.