Apple M1 GPUs retain register file data between compute shader dispatches from different processes. A sandboxed Metal attacker app can run a GPU reader shader that reads stale register values left by a separate sandboxed victim app. In the proof of concept, GPUVictim.app generates a fresh random 128-bit secret using SecRandomCopyBytes and loads it into GPU registers. GPUAttacker.app, a separate sandboxed app, recovers the exact secret from stale GPU register state. NOTE: The vendor stated that this behavior affects only legacy hardware and has already been addressed at the hardware level in current-generation Apple Silicon.

firefox: thunderbird: Memory corruption in Apple GPU drivers

Certain WebGL operations on Apple silicon M series devices could have lead to an out-of-bounds write and memory corruption due to a flaw in Apple's GPU driver. *This bug only affected the application on Apple M series hardware. Other platforms were unaffected.* This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Firefox ESR < 115.18, Thunderbird < 133, Thunderbird < 128.5, and Thunderbird < 115.18.