Ubuntu Security Notice USN-257-1 – Jim Meyering discovered that tar did not properly verify the validity of certain header fields in a GNU tar archive. By tricking an user into processing a specially crafted tar archive, this could be exploited to execute arbitrary code with the privileges of the user.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/44169/USN-257-1.txt
Source: https://packetstormsecurity.com/files/44169/Ubuntu-Security-Notice-257-1.html