Ubuntu Security Notice USN-326-1 – Yan Rong Ge discovered that heartbeat did not set proper permissions for an allocated shared memory segment. A local attacker could exploit this to render the heartbeat service unavailable causing a denial of service condition.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/48659/USN-326-1.txt
Source: https://packetstormsecurity.com/files/48659/Ubuntu-Security-Notice-326-1.html