I'd try a search for 'automated penetration testing' on your favorite search engine. There seem to be quite a few result. But beware, these things could easily

I'd try a search for 'automated penetration testing' on your favorite search engine. There seem to be quite a few result. But beware, these things could easily lure you into a false sense of security by not finding a big gaping hole in your security. Note that sign in and sign up isn't the only possible vulnerability. For example do you check that a signed-in user can only change his own information, and not other people's data by simply changing a user ID in an URL or in some hidden form data?