An untethered jailbreak known as ‘UnthreadedJB’ has been released for the CDMA iPhone 4 running iOS 5.1. Prior to this, no program supported an untethered jailbreak for iOS 5.1 (absinthe required 5.1.1 and redsn0w was tethered only). The jailbreak has been confirmed working by many people, and the team behind the jailbreak have no real names other than ‘UnthreadedJB’ It is most likely that the jailbreak uses previous exploits released by well known members of the jailbreak community.