So far i have been able to use cheat engine and hack the XP. You hafta be in a match for it to work though. Solo, Challenge, it works best that way. Start with 0 and then just keep looking for your in game XP until you find it and boost it up.
Thats all i got so far though. At times i swear people are using aimbots, but i would also like to see some more diverse hacks or just some unlockers. That way people can avoid doing the annoying challenges to unlock weapons and such.