Ubuntu Security Notice 441-1 – A flaw was discovered in Squid’s handling of the TRACE request method which could lead to a crash. Remote attackers with access to the Squid server could send malicious TRACE requests, and cause a denial of service.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/55389/USN-441-1.txt
Source: https://packetstormsecurity.com/files/55389/Ubuntu-Security-Notice-441-1.html