Hot on the heels of Geohot’s Limera1n tool for jailbreaking some iPhone and iPod touch models running iOS 4.1, the folks at the iPhone Dev Team have launched a new tool based on the same exploit. In a nutshell what that means is you can use the new greenpois0n tool to jailbreak the iPhone 4, iPhone 3GS, iPad, or 3rd or 4th generation iPod touch as long as those devices are running iOS 4.1.
Greenpois0n was due out this weekend, but Geohot surprised the iPhone hacking community by launching his software first, using a different exploit than the one greenpois0n was originally based on. Rather than alert Apple to two separate security holes in iOS 4.1, the iPhone Dev Team decided to delay their launch in order to retool the software and make use of the same exploit as Limera1n. That means even if Apple released a software update that removes the security hole, the Dev Team can go back to plan A and release a new version of greenpois0n using the other exploit.
For now you can only run greenpois0n from a Windows PC, but a Mac-based tool is coming soon. There will also be a future release that will add support for the 2nd generation iPod touch and the new Apple TV.
Once you jailbreak your device you’ll be able to install applications that aren’t available in the iTunes App Store and access settings that aren’t normally made available.
Update: There are now Windows and Linux utilities for running greenpois0n. An OS X version is still in the works.