Interestingly, no kernel vulnerability or anything is mentioned.
As far as I know, any parsing code for iMessages should run within the BlastDoor sandbox – is there another vulnerability in the chain that is not reported here?
One CVE is in Wallet and Citizen Lab mention PassKit. My guess is that BlastDoor deserializes the PassKit payload successfully, then sends it to PassKit which subsequently decodes a malicious image outside of BlastDoor.
It may be the case that either the kernel vulnerability hasn't been analyzed or fixed yet, or that they were not able to capture it. Many of these exploits have multiple stages and grabbing the later ones is difficult.
As far as I know, any parsing code for iMessages should run within the BlastDoor sandbox – is there another vulnerability in the chain that is not reported here?