Preface: AMD explain this design flaw. Do you have any queries?

Background: Ryzen is multi-core X86 (64) microprocessors. AMD made its own as an extension of the x86 instruction set. In some AMD processors using frequency scaling .

CPU Frequency Scaling is a feature that enables the operating system to scale the CPU frequency up or down to save power. Depending on the system load the CPU frequencies can be scaled automatically, this is in response to the ACPI events. It can also be manually done by using some programs.

Vulnerability details: A potential power side-channel vulnerability in AMD processors may allow an authenticated attacker to monitor the CPU power consumption as the data in a cache line changes over time potentially resulting in a leak of sensitive information.

Ref: Hertzbleed is a hardware security attack which describes exploiting dynamic frequency scaling to reveal secret data. The attack is a kind of timing attack, bearing similarity to previous power analysis vulnerabilities. Hertzbleed is more dangerous than power analysis, as it can be exploited by a remote attacker.

Official announcement: For details, please refer to the link – https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7006.html