Download Greenpois0n RC5 for iOS 4.2.1

The GreenPois0n RC5 Jailbreak tool has been released. This version of the tool allows users to jailbreak their devices running iOS 4.2.1 (untethered).

[NOTE] Before you download and use the following tool keep in mind that jailbreaking may void the warranty of your device. It may also cause device malfunction or loss of data if you don't understand what you are doing. So please proceed at your own risk.

• Download GreenPois0n RC5 (Windows | Mac | Linux)
• Download iOS 4.2.1 here

You can follow the instructional video which follows: