For PlaidCTF2014, Eindbazen and fail0verflow joined forces as 0xffa, the Final Fail Alliance. Don’t miss out on other write-ups at fail0verflow’s site!
The harry_potter pwnable is a network service that does not appear to do a whole lot:
$ nc 126.96.36.199 666
If you guess the password, I will give you a reward!
Running the binary in strace shows what is going on: