A local user can trigger a denial of service by exploiting a flaw in the SSSD PAM GSSAPI responder – cached connection state is freed without clearing the reference pointer, causing the service to read invalid memory when a new request is received on the same stale connection. The resultant crash interrupts authentication services and can render the system unusable until the service is restarted. The weakness is identified as a form of resource exhaustion and improper memory handling.

Affected products are Red Hat Enterprise Linux 10, 6, 7, 8, and 9, as well as Red Hat OpenShift Container Platform 4. All these systems run the SSSD service that provides authentication integration.

The CVSS score of 4.7 indicates a moderate severity rating; the EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog. The attack requires a local user to send a specially crafted request over an existing GSSAPI connection. If successful, it leads to an application crash and a temporary denial of authentication services, affecting availability. The exploit is constrained to local privilege and does not require network exposure, which limits its attack surface to compromised or root users within the host.