Ubuntu Security Notice 893-1 – Ronald Volgers discovered that the mount.cifs utility, when installed as a setuid program, suffered from a race condition when verifying user permissions. A local attacker could trick samba into mounting over arbitrary locations, leading to a root privilege escalation.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/85737/USN-893-1.txt
Source: https://packetstormsecurity.com/files/85737/Ubuntu-Security-Notice-893-1.html