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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
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
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.
Sources
Also known as DEBIAN-CVE-2025-24031, GHSA-wvr3-c9x3-9mff, UBUNTU-CVE-2025-24031.