Google security hackers have confirmed a confidential computing compromise that targets AMD Zen-based devices.

AMD advisory warns about a new high-severity security flaw The bug affects Zen 1 to Zen 4 CPUs Abuse could lead to the loss of SEV-based protection of a confidential guest Chipmaking giant AMD has confirmed it recently patched a high-severity vulnerability affecting its Zen 1 to Zen 4 CPUs.

Googlers have not only figured out how to break AMD's security – allowing them to load unofficial microcode into its processors to modify the silicon's behavior – but also demonstrated this by producing a microcode patch that makes the chips always output 4 when asked for a random number.

AMD has fixed a security exploit that could cause the loss of SEV-based protection in CPUs dating back to Epyc Naples 7001 series.