---
title: "HOST-FS-009 Default File Creation Mask Too Permissive"
canonical: https://openvapt.com/checks/HOST-FS-009.html
html: https://openvapt.com/checks/HOST-FS-009.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-009 Default File Creation Mask Too Permissive

Checks that the default umask makes new files unreadable to other users (027 or stricter).

- Domain: Server
- Severity: Low
- 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:L/I:N/A:N`
- CIS Controls v8: 3.3
- NIST CSF 2.0: PR.AA-05, PR.DS-01
- CWE: CWE-276
- NIST SP 800-53 Rev. 5: AC-6, CM-6
- Benchmark topic: Default user umask (topic only, no benchmark text)

## Why It Matters

With umask 022 every new file is readable by every local user, including configuration exports, reports and backups created by administrators.

## How It Detects

Reads UMASK from /etc/login.defs. Values that leave the 'other' read bit open (for example 022 or 002) fail.

## How to Fix

Set  UMASK 027  in /etc/login.defs (and, if used, in /etc/profile or /etc/bash.bashrc).

## How to Verify

```
grep '^UMASK' /etc/login.defs
```

## Learn the Theory

- [P1 Linux Server Hardening](https://openvapt.com/academy/p1.md)
- [P15 Access Control: Accounts, Sudo and Logins](https://openvapt.com/academy/p15.md)

## References

- [login.defs(5), Linux man-pages](https://man7.org/linux/man-pages/man5/login.defs.5.html)
- [umask(2), Linux man-pages](https://man7.org/linux/man-pages/man2/umask.2.html)

## Source Code

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

Run it: `openvapt scan --only HOST-FS-009`. Read it offline: `openvapt explain HOST-FS-009`.

---

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