First public macOS kernel memory corruption exploit on Apple M5
97 points by quadrige 3 hours ago | 14 comments
yieldcrv 39 minutes ago
from what they demonstrated, this seems to only be a $100,000 exploit in Apple's bug bounty platform, but if they package it right, it could be a $1.5 million exploit
replyThey simply have to show it against a beta version of MacOS, and frame it as unauthorized access, and maybe from locked mode if possible
(https://www.usenix.org/publications/loginonline/data-only-at...)
This makes more sense. You don't trigger MTE since you're not doing anything for force MTE to take action the program isn't actually changing.
My other question would be, why didn't apple use fbounds checking here? They've been doing it aggressively everywhere else.
MTE plus fbounds checking everywhere should lead to an extremly hardened OS
1. it’s to performance sensitive
Or
2. The os is so darn large it’s hard to recompile everything
Arm published the Memory Tagging Extension (MTE) specification in 2019 as a tool for hardware to help find memory corruption bugs. MTE is a memory tagging and tag-checking system, where every memory allocation is tagged with a secret. The hardware guarantees that later requests to access memory are granted only if the request contains the correct secret. If the secrets don’t match, the app crashes, and the event is logged. This allows developers to identify memory corruption bugs immediately as they occur.
https://support.apple.com/guide/security/operating-system-in...