CVE-2025-24032 — PAM-PKCS#11 vulnerable to authentication bypass with default value for `cert_policy` (`none`)

Affected: OpenSC pam_pkcs11

PAM-PKCS#11 is a Linux-PAM login module that allows a X.509 certificate based user login. Prior to version 0.6.13, if cert_policy is set to none (the default value), then pam_pkcs11 will only check if the user is capable of logging into the token. An attacker may create a different token with the user's public data (e.g. the user's certificate) and a PIN known to the attacker. If no signature with the private key is required, then the attacker may now login as user with that created token. The default to *not* check the private key's signature has been changed with commit commi6638576892b59a99389043c90a1e7dd4d783b921, so that all versions starting with pam_pkcs11-0.6.0 should be affected. As a workaround, in `pam_pkcs11.conf`, set at least `cert_policy = signature;`.

USN-7363-1 — pam-pkcs11 vulnerabilities

Affected: Ubuntu:Pro:16.04:LTS: pam-pkcs11, Ubuntu:Pro:18.04:LTS: pam-pkcs11, Ubuntu:20.04:LTS: pam-pkcs11, Ubuntu:22.04:LTS: pam-pkcs11, Ubuntu:24.04:LTS: pam-pkcs11

Marcus Rückert and Matthias Gerstner discovered that PAM-PKCS#11 did not properly handle certain return codes when authentication was not possible. An attacker could possibly use this issue to bypass authentication. This issue only affected Ubuntu 24.04 LTS and Ubuntu 24.10. (CVE-2025-24531)

It was discovered that PAM-PKCS#11 did not require a private key signature for authentication by default. An attacker could possibly use this issue to bypass authentication. (CVE-2025-24032)

Most recent entries from all

CVE-2025-24032 — PAM-PKCS#11 vulnerable to authentication bypass with default value for `cert_policy` (`none`)

USN-7363-1 — pam-pkcs11 vulnerabilities