Due to a security vulnerability in Ryzen processors, the SMT function should be disabled in the BIOS.
Many Ryzen processors in recent years have been affected by a security vulnerability.
AMD has relied on a multi-chip module design since the Zen 2 and Zen 3 chip generations: The manufacturer accommodates the individual cores, memory channels and graphics units on several dies. Advantage in production: If a module is defective, the entire package does not have to be disposed of. Instead, the individual modules can also be exchanged. However, this approach now creates a new exploit in the scheduler’s queue. In this way, malicious code could migrate to the computer, which unintentionally leaks content to third parties.
Zen 2 and Zen 3 in focus
The attack option called Scheduler Queue Contention Side Channel ( SQUIP ) exploits the queues of the scheduler in order to be able to read the currently executed accesses. Intel is protected from this vulnerability because there is only one queue. With chips from AMD and Apple, on the other hand, there is a theoretical attack vector that can be exploited. The AMD processors with multi-chip module design (MCM) are affected, specifically Zen 2 and Zen 3.
SMT shutdown recommended
According to scientists at the Technical University of Graz, a prerequisite for an attack is the infiltration of malicious code and a lengthy process of importing the same code onto the processor. Only then can activities on the system be precisely traced. Apple chips like the M1 aren’t vulnerable because they don’t support Hyperthreading. So if you want to be on the safe side with your Ryzen processor with MCM, you should temporarily disable hyperthreading (SMT) in the BIOS. AMD has already recognized the security gap and classifies it as “medium”. A list of potentially vulnerable processors from AMD can also be found on the help page.
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