Such a vulnerability would almost certainly require the phone to be powered on, and for the boot time pin code entered (to allow the phone to decrypt user-space

Such a vulnerability would almost certainly require the phone to be powered on, and for the boot time pin code entered (to allow the phone to decrypt user-space data). It's mechanism of action would be along the lines of reading the PIN code out of memory, trick the user into entering their PIN into a fake screen, read the decryption key out of memory, of make un-authorised calls to decrypt data. In the case that we're all talking about, this capability would be pointless. On the other hand, could a 3rd party create a crack that manipulated the PIN reset counter, in a way similar to that being requested by the FBI? Potentially with the right vulnerability. (Note, I've only skimmed the Apple white paper, so I may be wrong here).