Similarly the college I attended required a five or six (can't remember now) digit number required for access to class registration. The idea was that you would talk to your advisor beforehand so you didn't sign up for the wrong thing I guess. My advisor seemed to be pretty uninterested in meeting with me over email (never responded to multiple attempts), so I gave up and brute forced it.
Class registration was done by most with the web interface, but I opted to connect to the backing mainframe via a 3270 terminal emulator. Doing so allowed me to write a simple expect script passing in an increasing number as fast as the connection would allow. I didn't bother with rate limiting and am surprised nobody noticed. Took me about 30 minutes and I was in! I was able to use that script at least twice and I wished I had thought of writing it sooner.
My advisor was a jerk who scheduled appointments for about 14 people at the same time, the day he left the country for a month. Wish I had this then, that following semester was brutal.
Class registration was done by most with the web interface, but I opted to connect to the backing mainframe via a 3270 terminal emulator. Doing so allowed me to write a simple expect script passing in an increasing number as fast as the connection would allow. I didn't bother with rate limiting and am surprised nobody noticed. Took me about 30 minutes and I was in! I was able to use that script at least twice and I wished I had thought of writing it sooner.