Jailbreak iPhone 3GS, iPhone 4 Using GreenPois0n RC5 Untethered Jailbreaking Tool for iOS 4.2.1 [Mac]

Earlier today, we reported that the Chronic Dev-Team has released GreenPois0n RC5 untethered jailbreak tool for iOS 4.2.1 (iOS 4.1 also supported), now we’re putting up instructions on how to jailbreak your iPhone 3GS and iPhone 4 with Greenpois0n RC5 for Mac, courtesy of iClarified.

Important:

Greenpois0n recommends a clean restore before continuing. Do not update to iOS 4.1 or iOS 4.2.1 if you need the unlock. Ultrasn0w does not support that baseband yet. The only exception is the iPhone 4. You can update to iOS 4.2.1 without upgrading your baseband by using TinyUmbrella. Start TSS Server->Start iTunes->Plug in your iPhone->Restore 4.2.1->Error 1013->Put phone into DFU Mode->Launch Greenpois0n.

Step One
Launch your web browser and go to www.greenpois0n.com. Click the Mac link at the bottom of the screen.

 

Step Two
Upon prompt, save the greenpois0n-osx_rc5.zip file you want to download on your desktop. Extract the files and launch the greenpois0n application.

 Step Three
Now power off your iPhone 3GS or iPhone 4 and connect it to the computer. Once connected, click the large Jailbreak button

Step Four
Greenpois0n will now tell you how to place your iPhone into DFU mode, after which you will be asked to press and hold the sleep button for 3 seconds.

Continue holding sleep; press and hold home for 10 seconds.

You may release the sleep button but keep holding the Home button. Do not release the Home button at this point!.

Step Five
The jailbreak begins once your iPhone is successfully in DFU mode.

Step Six
You may release the Home button once Greenpois0n informs you that it has completed the jailbreak. Clicking the Complete button will close the application on your computer. You will notice some verbose mode text scrolling on your device.

Step Seven
After the iPhone restarts you will also notice a new Loader application on your Springboard. Tap on it to launch it.

Step Eight
After launching Loader application, select Cydia and then press the large Install Cydia button that appears.

Step Nine
You may remove Loader by pressing the Options button then the large red Remove Loader.app button once Cydia has installed successfully.

Step Ten
Restart your iPhone then run Cydia. Let it do all the necessary updates.

And Voila! There you have it, an untethered jailbreak on your iPhone running iOS 4.2.1 using Greenpois0c RC5 for Mac.

Did you find this tutorial helpful? Experienced any issues in the process? Let us know in your comments below!