Ubuntu Security Notice USN-724-1 – Joshua Morin, Mikko Varpiola and Jukka Taimisto discovered that Squid did not properly validate the HTTP version when processing requests. A remote attacker could exploit this to cause a denial of service (assertion failure).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/75222/USN-724-1.txt
Source: https://packetstormsecurity.com/files/75222/Ubuntu-Security-Notice-724-1.html