---
title: "HOST-AUD-009 Audit Daemon Ignores a Full Log Disk"
canonical: https://openvapt.com/checks/HOST-AUD-009.html
html: https://openvapt.com/checks/HOST-AUD-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-AUD-009 Audit Daemon Ignores a Full Log Disk

Checks that auditd is told what to do when its log file is full or the disk runs low, rather than silently dropping events.

- Domain: Server
- Severity: Low
- Control category: Logging and Monitoring
- Fix effort: low
- CVSS v3.1 vector: `CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N`
- CIS Controls v8: 8.3
- NIST CSF 2.0: PR.PS-04
- CWE: CWE-778
- OWASP Top 10 2021: A09:2021
- NIST SP 800-53 Rev. 5: AU-4, AU-5
- Benchmark topic: Audit log storage and full-disk actions (CIS Controls v8 8.3) (topic only, no benchmark text)

## Why It Matters

With max_log_file_action = ignore the log grows until the disk is full; with suspend auditing simply stops. An unset space_left_action means nobody is warned before that happens. Either way an attacker who fills the disk switches auditing off.

## How It Detects

Reads max_log_file_action, space_left_action and admin_space_left_action from /etc/audit/auditd.conf. Each must be set and must not be ignore or suspend. Skipped when auditd is not installed; Incomplete when the file exists but cannot be read.

## How to Fix

In /etc/audit/auditd.conf set  max_log_file_action = keep_logs  (or rotate with enough num_logs),  space_left_action = email  (or syslog or exec), and  admin_space_left_action = halt  or  single  as policy requires, then systemctl restart auditd. Caution: admin_space_left_action = halt or single stops the server or drops it to single-user mode when the audit disk fills; choose it only where losing audit records is worse than downtime, and give /var/log/audit room and monitoring first.

## How to Verify

```
grep -E '^(max_log_file_action|space_left_action|admin_space_left_action)' /etc/audit/auditd.conf
```

## Learn the Theory

- [P21 Audit Logging and Monitoring Depth](https://openvapt.com/academy/p21.md)

## References

- [auditd.conf(5), Linux man-pages](https://man7.org/linux/man-pages/man5/auditd.conf.5.html)
- [NIST SP 800-92, Guide to Computer Security Log Management](https://csrc.nist.gov/pubs/sp/800/92/final)

## Source Code

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

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

---

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