I searched in google for "ASP.Net 4.0.30319 vulnerability " keyword. finally,I found "Microsoft ASP.NET Forms Authentication Bypass" in below link:
http://dl.packetstormsecurity.net/1203-exploits/SA-20120328-1.txt
but I don't know how to penetration test this vulnerability. otherwords , if someone get me one application that implemented by ASP.Net 4.0.30319 ,I can't proof exists this vulnerability.
My question is how to prove the existence of this vulnerability in a ASP.NET Applications? Do the necessary steps to patch this vulnerability has done by programer?