Post Syndicated from original https://lwn.net/Articles/897914/

Today’s branded, logo-equipped vulnerability is known as Hertzbleed; it affects x86
processors (at least) and can be exploited in some situations to extract
cryptographic keys from a remote server.

Hertzbleed takes advantage of our experiments showing that, under
certain circumstances, the dynamic frequency scaling of modern x86
processors depends on the data being processed. This means that, on
modern processors, the same program can run at a different CPU
frequency (and therefore take a different wall time) when
computing, for example, 2022 + 23823 compared to 2022 + 24436.