Sinkclose is a security vulnerability in certain AMD microprocessors dating back to 2006 that was made public by IOActive security researchers on August 9, 2024.
[1] IOActive researchers Enrique Nissim and Krzysztof Okupski presented their findings at the 2024 DEF CON security conference in Las Vegas[2] in a talk titled "AMD Sinkclose: Universal Ring-2 Privilege Escalation".
AMD said it would patch all affected Zen-based Ryzen, Epyc and Threadripper processors but initially omitted Ryzen 3000 desktop processors.
Sinkclose affects the System Management Mode (SMM) of AMD processors.
It can only be exploited by first compromising the operating system kernel.