CVE-2022-4283

Se encontró una vulnerabilidad en X.Org. Este fallo de seguridad se produce porque la función XkbCopyNames dejó un puntero colgante a la memoria liberada, lo que provocó un acceso a la memoria fuera de los límites en solicitudes posteriores de XkbGetKbdByName. Este problema puede provocar una elevación de privilegios locales en sistemas donde el servidor X se ejecuta de forma privilegiada y remota. Ejecución de código para sesiones de reenvío ssh X.

A vulnerability was found in X.Org. This issue occurs because the XkbCopyNames function leaves a dangling pointer to freed memory, resulting in out-of-bounds memory access on subsequent XkbGetKbdByName requests. This flaw can lead to local privilege elevation on systems where the X server runs privileged and remote code execution for ssh X forwarding sessions.

This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the handling of XkbCopyNames requests. The issue results from the lack of validating the existence of an object prior to performing further free operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.