Affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Hardened Images, Red Hat OpenShift Container Platform 4

A flaw was found in sssd. When authenticating with a YubiKey, the SSSD PAM responder can crash due to a use-after-free vulnerability, where a memory pointer is incorrectly handled. A local attacker could exploit this flaw by manipulating smartcard or YubiKey contents, leading to a denial of service that disrupts authentication. This vulnerability also presents a potential for privilege escalation, although it is difficult to exploit.

Affected: Ubuntu:22.04:LTS: sssd, Ubuntu:24.04:LTS: sssd, Ubuntu:26.04:LTS: sssd

It was discovered that the SSSD PAM responder may crash if a physically proximate attacker manipulates a smartcard or Yubikey. Non-malicious physically proximate users may not be able to log in depending upon the details of their legitimate smartcard or Yubikey.