Pod2g, the guy behind SHAtter and the untethered iOS 4.2.1 exploit for GreenPois0n has discovered yet another vulnerability in iOS for iPhone, iPad and iPod touch which can possibly be used on iOS 4.2.1 and 4.3 as well.

Hey, another untethered vulnerability found ! http://twitpic.com/3ujze3
Look at the registers, all are controllable

At this point though, it is unclear on whether the vulnerability found is in the bootrom like Limera1n, or if it is of the userland nature.
Since the upcoming version of GreenPois0n is already set to bring untethered jailbreak for iOS 4.2.1, this vulnerability is likely going to be saved for the future firmwares like iOS 4.3 and beyond.

As always, we will keep you updated. Stay tuned for more! (Twitter 1, 2)