AMD has reversed course and decided to patch the new 'Sinkclose' vulnerability on Ryzen 3000 desktop processors after all. AMD updated its SMM Lock Bypass Security Bulletin, which now includes a fix for Ryzen 3000 desktop CPUs (codenamed Matisse) scheduled for tomorrow, August 20.

Sinkclose is a significant security vulnerability that has affected virtually all AMD processors since 2006. The vulnerability takes advantage of a flaw within the System Management Mode (SMM) in affected chips, allowing hackers to execute code within the SMM. This makes attacks made from the SMM virtually impossible to detect via antivirus software. The vulnerability also makes any malware installed extremely difficult to detect and delete and can even persist after an OS reinstall.

Thankfully, this vulnerability is difficult to exploit and requires hackers to use a different exploit to gain access to the computer's kernel before Sinkclose can be used to access the SMM. Regardless, this is a serious vulnerability, no matter how you look at it, and one that AMD is working to patch as soon as possible.

AMD had previously confirmed that it would patch the Sinkclose vulnerability on all its outgoing Ryzen CPUs, including the Zen 1 architecture chips. These chips include various Zen 1, Zen 2, Zen 3, and Zen 4 parts, including server, mobile, and desktop.

The only exception was the Ryzen 3000 (Matisse) desktop processors, which, for some reason, AMD initially did not list support for regarding this vulnerability specifically. Matisse was the only Zen 2-based CPU lineup AMD initially did not plan to patch. Ryzen Threadripper 3000, Threadripper Pro 3000WX, Zen 2 EPYC (7002), Ryzen 3000 mobile, and Ryzen 3000/4000 APUs all were in AMD's original plans to be patched (and still are).

Thankfully, whether it was a typing error or not, AMD has officially confirmed a Sinkclose patch for Matisse desktop chips. The update will come out tomorrow in some mysterious format. Strangely, AMD did not disclose what microcode update will feature this fix for Matisse processors, even though AMD lists a microcode version for every other CPU lineup that is getting the fix.

Regardless, AMD is patching the Sinkclose vulnerability in vanilla desktop Ryzen 3000 series processors, which will arrive tomorrow.