# CVE-2025-24031: PAM-PKCS#11 vulnerable to segmentation fault on ctrl-c/ctrl-d when asked for PIN

> An attacker can cause a denial of service by triggering a segmentation fault in the PAM-PKCS#11 module when a user cancels the PIN prompt.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Feb 2025
- **Updated:** 10 Feb 2025
- **Also known as:** DEBIAN-CVE-2025-24031, GHSA-wvr3-c9x3-9mff, UBUNTU-CVE-2025-24031

## What is CVE-2025-24031?

CVE-2025-24031 is a medium-severity vulnerability in OpenSC pam_pkcs11, published on 10 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

PAM-PKCS#11 is a Linux-PAM login module that allows a X.509 certificate based user login. In versions 0.6.12 and prior, the pam_pkcs11 module segfaults when a user presses ctrl-c/ctrl-d when they are asked for a PIN. When a user enters no PIN at all, `pam_get_pwd` will never initialize the password buffer pointer and as such `cleanse` will try to dereference an uninitialized pointer. On my system this pointer happens to have the value 3 most of the time when running sudo and as such it will segfault. The most likely impact to a system affected by this issue is an availability impact due to a daemon that uses PAM crashing. As of time of publication, a patch for the issue is unavailable.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-24031?


## How do I fix CVE-2025-24031?

No fix published yet.

## Is CVE-2025-24031 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-24031 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-24031 and fix it if it is affected.

What it is: CVE-2025-24031 is a medium-severity vulnerability in OpenSC pam_pkcs11, published on 10 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-24031 exists.

Affected product: OpenSC pam_pkcs11. 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-2025-24031/ (Markdown: https://insights.sbomify.com/CVE-2025-24031/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-24031
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-24031
- OSV: https://osv.dev/vulnerability/CVE-2025-24031

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-24031/
Summaries are generated and may contain mistakes; the official description above is the record.