Ubuntu Security Notice USN-146-1 – Nobuhiro IMAI discovered that the changed default value of the Module#public_instance_methods() method broke the security protection of XMLRPC server handlers. A remote attacker could exploit this to execute arbitrary commands on an XMLRPC server.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/38363/USN-146-1.txt
Source: https://packetstormsecurity.com/files/38363/Ubuntu-Security-Notice-146-1.html