Software installed and run as a non-privileged user may conduct improper GPU system calls to trigger reads of stale data that can lead to kernel exceptions and write use-after-free.
The Use After Free common weakness enumeration was chosen as the stale data can include handles to resources in which the reference counts can become unbalanced. This can lead to the premature destruction of a resource while in use.
Software installed and run as a non-privileged user may conduct improper GPU system calls to subvert GPU HW to write to arbitrary physical memory pages.
Kernel software installed and running inside a Guest VM may exploit memory shared with the GPU Firmware to write data outside the Guest's virtualised GPU memory.
A GPU kernel can read sensitive data from another GPU kernel (even from another user or app) through an optimized GPU memory region called _local memory_ on various architectures.