A flaw was found in the X.org server. Due to improperly tracked allocation size in _XkbSetCompatMap, a local attacker may be able to trigger a buffer overflow condition via a specially crafted payload, leading to denial of service or local privilege escalation in distributions where the X.org server is run with root privileges.
Se encontró un fallo en el servidor X.org. Debido a que el tamaño de asignación no se rastrea correctamente en _XkbSetCompatMap, un atacante local podría desencadenar una condición de desbordamiento de búfer a través de un payload especialmente manipulado, lo que provocaría una denegación de servicio o una escalada de privilegios locales en distribuciones donde el servidor X.org se ejecuta con privilegios de root.
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 XkbSetCompatMap requests. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.
