As most of you know, comex is currently working on an untethered solution for jailbreaking iOS 4.2.1, but today, the iPhone Dev Team has unveiled one of the many their plans! They got up their sleeves with a backup plan for an untethered iOS 4.2.1 jailbreak for all devices.
As they have mentioned, this is not a new exploit, it’s a ‘backup plan’ as comex is working on a more extensible one, but this method is also generalizable. The method only works if you have already saved SHSH blobs of your iOS device. Anyway, take a look at the video demo below and stay tuned as more updates come!