AppleIntelCapriController::GetLinkConfig trusts a user-supplied value in the structure input which it uses to index
a small table of pointers without bounds checking. The OOB-read pointer is passed to AppleIntelFramebuffer::validateDisplayMode
which will read a pointer to a C++ object from that buffer (at offset 2138h) and call a virtual method allowing trivial kernel code execution.

Tested on MacOS 10.13 (17A365) on MacBookAir5,2
 

capri_link_config.c 1.7 KB View Download