Debian Security Advisory 1249-1 – Several vulnerabilities have been discovered in the X Window System, which may lead to privilege escalation or denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/53694/dsa-1249-1.txt
Source: https://packetstormsecurity.com/files/53694/Debian-Linux-Security-Advisory-1249-1.html