CVE-2025-24031
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedPAM-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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn PAM-PKCS#11 versions 0.6.12 and prior, the pam_pkcs11 module crashes when users press ctrl-c/ctrl-d or enter no PIN when prompted. The pam_get_pwd function fails to initialize the password buffer pointer in these scenarios, and the subsequent cleanse function attempt to dereference this uninitialized pointer causes a segfault.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- None
- Scope
- X
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify PAM-PKCS#11 installation and versionRun 'rpm -qa | grep pam_pkcs11' (RHEL/CentOS) or 'dpkg -l | grep pam-pkcs11' (Debian/Ubuntu) to list installed packages, or check for /lib/security/pam_pkcs11.so or /usr/lib/security/pam_pkcs11.soAffected if Version is 0.6.12 or prior, or package is installed without version visible (assume affected)
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Locate the pam_pkcs11 module fileSearch for pam_pkcs11.so using 'find /lib* /usr/lib* -name pam_pkcs11.so 2>/dev/null' to confirm the module is present on the systemAffected if The pam_pkcs11.so file exists on the system
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Check PAM configuration for pam_pkcs11 usageReview PAM configuration files in /etc/pam.d/ (common files: system-auth, password-auth, login, sshd, sudo) using 'grep -r pam_pkcs11 /etc/pam.d/'Affected if pam_pkcs11 is referenced in any PAM configuration file (indicates the module is loaded for authentication)
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Verify certificate-based authentication is configuredCheck for pam_pkcs11 configuration in /etc/pam_pkcs11/ directory, especially pam_pkcs11.conf, and look for certificate mapper settingsAffected if Certificate-based authentication using pam_pkcs11 is configured in /etc/pam_pkcs11/
A system is affected if PAM-PKCS#11 version 0.6.12 or prior is installed and the pam_pkcs11 module is loaded in any PAM configuration for authentication purposes.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUntil an official patch is released, monitor affected systems for daemon crashes and consider restricting certificate-based authentication methods or implementing additional monitoring for PAM-related failures.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-24031 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-24031 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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