Aman Khan

I am web app. pen tester and today i found something strange that a web app. is running on 1.7.2 and this is an outdated version so i am also pretty sure that there will be some exploit also so please tell me some

I aman was trying to hack into a login page but it contain more then one form ex i wanna hack username as well as pass at the same time. Some of you suggest me to hack username first then pass yeah ? but no there no error showing if username is wrong. please help me out.