# CVE-2023-25824: mod_gnutls contains Infinite Loop on request read timeout

> An attacker can cause a denial of service by triggering an infinite loop in mod_gnutls during TLS read timeouts, consuming CPU resources.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Feb 2023
- **Updated:** 10 Mar 2025
- **Also known as:** GHSA-6cfv-fvgm-7pc8, UBUNTU-CVE-2023-25824

## What is CVE-2023-25824?

CVE-2023-25824 is a high-severity denial of service vulnerability in airtower-luna mod_gnutls, published on 23 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Mod_gnutls is a TLS module for Apache HTTPD based on GnuTLS. Versions from 0.9.0 to 0.12.0 (including) did not properly fail blocking read operations on TLS connections when the transport hit timeouts. Instead it entered an endless loop retrying the read operation, consuming CPU resources. This could be exploited for denial of service attacks. If trace level logging was enabled, it would also produce an excessive amount of log output during the loop, consuming disk space. The problem has been fixed in commit d7eec4e598158ab6a98bf505354e84352f9715ec, please update to version 0.12.1. There are no workarounds, users who cannot update should apply the errno fix detailed in the security advisory.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2023-25824?

It affects 1 product.


Products: Mod Gnutls Project Mod Gnutls.

## How do I fix CVE-2023-25824?

No fix has been published for CVE-2023-25824 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-25824 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25824 exists.

## Other vulnerabilities in airtower-luna mod_gnutls

- [CVE-2026-33307](https://insights.sbomify.com/CVE-2026-33307/): mod_gnutils has stack-based buffer overflow caused by a long client certificate chain (high 7.5)
- [CVE-2009-5144](https://insights.sbomify.com/CVE-2009-5144/): Auth bypass in n/a (high 7.5)
- [CVE-2026-33308](https://insights.sbomify.com/CVE-2026-33308/): mod_gnutls missing key purpose check in client certificate verification (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-25824 and fix it if it is affected.

What it is: CVE-2023-25824 is a high-severity denial of service vulnerability in airtower-luna mod_gnutls, published on 23 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25824 exists.

Affected product: airtower-luna mod_gnutls. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-25824/ (Markdown: https://insights.sbomify.com/CVE-2023-25824/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-25824
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-25824
- OSV: https://osv.dev/vulnerability/CVE-2023-25824

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-25824/
Summaries are generated and may contain mistakes; the official description above is the record.