Ubuntu Security Notice 629-1 – Various flaws in the mozilla-thunderbird package have been addressed including improper handling, weaknesses, denial of service, and code execution issues.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/68498/USN-629-1.txt
Source: https://packetstormsecurity.com/files/68498/Ubuntu-Security-Notice-629-1.html