Ubuntu Security Notice 931-2 – USN-931-1 fixed vulnerabilities in FFmpeg. The update introduced a regression when trying to play certain multimedia files. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that FFmpeg contained multiple security issues when handling certain multimedia files. If a user were tricked into opening a crafted multimedia file, an attacker could cause a denial of service via application crash, or possibly execute arbitrary code with the privileges of the user invoking the program.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/88930/USN-931-2.txt
Source: https://packetstormsecurity.com/files/88930/Ubuntu-Security-Notice-931-2.html