The exploit, which was demoed (untethered jailbreak demo) last night, and which successfully managed to find its way to untethered jailbreaking solution will not release these days until Apple releases iOS 4.3.1. Lets check it out what Stefan Esser (the hacker behind the exploit) is to say -
i0n1c: With Apple already baking 4.3.1 the first one releasing an iOS 4.3 jailbreak will pretty much burn the exploit
i0n1c: Well Apple should release 4.3.1 very soon, because tomorrow everybody knows that @0xcharlie popped an iPhone 4 at #pwn2own through Safari.
From the above statement if you are quite confused or can’t able to figure out who the person, Stefan Esser is talking about, then let me tell you that, this is the guy who has successfully hacked an iPhone 4 at Pwn2Own 2011 hacking contest using an exploit found in Mobile Safari running iOS 4.2.1, and that vulnerability is also exists in iOS 4.3, but the thing is all devices running the latest version of iOS are safe until hackers find a way to bypass the ASLR (Address Space Layout Randomization) found in supported iOS devices starting from iOS 4.3.
In an interview, Charlie Miller told that bypassing ASLR security in iOS 4.3 is harder to do than what most think it is,
If you update your iPhone today, the [MobileSafari] vulnerability is still there, but the exploit won’t work. I’d have to bypass DEP and ASLR for this exploit to work.
As of 4.3, because of the new ASLR, it will be much harder.
So for that reason the untethered jailbreaking solution is not look imminent..