1. iphoneunlocker's Avatar
    The GreenPois0n untethered jailbreak for iOS 4.2.1 was released a few minutes ago and I already took it for a spin on my older iPhone 3G sporting iOS 4.2.1.

    This step by step guide will show you how to use GreenPois0n to jailbreak your iPhone running iOS 4.2.1. Its worth noting that this version will not hacktivate your iPhone and that so far, there is only a Mac version

    Step 1: Make sure your iPhone is on iOS 4.2.1 as GreenPois0n will not work with any other firmware.

    Step 2: Download GreenPois0n from our downloads section.

    Step 3: Plug your iPhone to your computer via the USB cable then launch GreenPois0n. Click on the Jailbreak button.

    Step 4: As soon as you hit jailbreak, you will have to follow instructions for putting your iPhone into DFU mode:

    for more step and download link go to Tutorial: How to Jailbreak your iPhone 4.2.1 with GreenPois0n Unlock iPhone
    02-06-2011 10:37 PM
  2. BryanTheRed's Avatar
    Good write up but would be better suited for the jailbreak forum...
    02-07-2011 05:01 AM