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Processor vulnerability

CVE-2023-20575

The power reporting interface (RAPL) can let an attacker follow a program running inside an SEV guest; AMD rates it low and recommends constant-time code.

Name
Power side channel on SEV guests
Vulnerability
AMD SEV, SEV-ES and SEV-SNP
Kind
Other
CVE published
2023-07-11 CVE record
Advisories
AMD-SB-3004
The researchers applied the method of the 2020 Platypus attack, reading the Running Average Power Limit counters, to code in a first-generation SEV guest; they did not test SEV-ES or SEV-SNP, whose encrypted register state is meant to resist it. AMD lists the first four EPYC generations as affected and gives no firmware fix: software that handles secrets should use constant-time and power side-channel resistant algorithms and avoid control flow that depends on secrets.

Affected processors

4 of the 4 microarchitectures listed are affected in all or some of their models.

What the sources say of each microarchitecture.
MicroarchitectureStatusDetailSource
ZenAffectedFirst generation EPYCamd.com
Zen 2AffectedSecond generation EPYCamd.com
Zen 3AffectedThird generation EPYCamd.com
Zen 4AffectedFourth generation EPYCamd.com

Mitigations

  • Programs: Constant-time and power side-channel resistant algorithms, and no control flow that depends on secrets. Source.

Sources

  1. AMD-SB-3004: AMD SEV VM Power Side Channel Security Bulletin