Exploiting a Flaw in Bitmap Handling in Windows User-Mode Printer Drivers

In this guest blog from researcher Marcin Wiązowski, he details CVE-2023-21822 – a Use-After-Free (UAF) in win32kfull that could lead to a privilege escalation. The bug was reported through the ZDI program and later patched by Microsoft. Marcin has graciously provided this detailed write-up of