A couple of hours ago, Chronic DevTeam finally released a new update for greenpois0n which allow us to apply an untethered jailbreak to our iOS devices running iOS 4.2.1 ( and iOS 4.1.1 ). Normally, unlockers should avoid this tool, because in order to use it you need to restore to a stock 4.2.1 FW which will update your baseband. But, thanks to TinyUmbrella, iPhone 4 owners who need to unlock, can update to iOS 4.2.1 and use greenpois0n without loosing the ability to unlock.
NOTE: iPhone 4 ONLY
Download and install TinyUmbrella
( if you didn’t already )
3. Load TinyUmbrella and Start TSS Server. To make sure it’s running, check out the logs…
4. Start iTunes
5. Plug-in your iPhone
6. Restore to iOS 4.2.1
7. You will get an Error 1013. That’s totally normal.
8. Put your iPhone in DFU