It’s been a busy day for jailbreakers since Chronic Dev-Team has released greenpois0n RC5 which jailbreaks your iPhone 4/3GS, iPod touch or iPad on iOS 4.2.1 completely untethered and we recently published a step-by-step guide on how to do it. However, that is only suitable for those who do not rely on a software unlock (ultrasn0w) for using their iPhone on an unsupported carrier. Now until a pwnage tool comes out for this, folks at FSM have posted a nice and quick guide for iPhone 4 users to jailbreak on iOS 4.2.1without updating their baseband and preserving ultrasn0w unlock.
Before you proceed, please note:
Download and install TinyUmbrella from here .
Download the official iOS 4.2.1 firmware for iPhone 4 here.
Load TinyUmbrella and Start TSS Server. To make sure it’s running, check out the logs…
Now Plug-in your iPhone 4.
Restore to official iOS 4.2.1 using the downloaded firmware
You will get an Error 1013. That’s totally normal.
Put your iPhone 4 in DFU mode and jailbreak it untethered using greenpois0n RC5 by following this step-by-step guide.
- Fixing issues with greenpois0n RC5 Untethered Jailbreak for iOS 4.2.1.
- How To Unlock iOS 4.2.1 On iPhone 3GS / 3G With Baseband Update To 06.15.00 Using PwnageTool 4.1.3 + Ultrasn0w 1.2 [Guide]