Secret disclosure via SMT scheduler contention
Published Aug 9, 2022 · Updated Sep 17, 2024
Information disclosure in AMD Zen 1 through Zen 4 processors with SMT allows local users to recover secrets via scheduler contention. Per-execution-unit scheduler queues are shared between sibling SMT threads, so a probing workload can infer a victim's instruction patterns from queue occupancy and pipeline-stall timing. An attacker must run on the same physical core as the victim; the demonstrated attack recovered RSA-4096 private keys from co-located processes and virtual machines.
Summary
What happened
Information disclosure in AMD Zen 1 through Zen 4 processors with SMT allows local users to recover secrets via scheduler contention. Per-execution-unit scheduler queues are shared between sibling SMT threads, so a probing workload can infer a victim's instruction patterns from queue occupancy and pipeline-stall timing. An attacker must run on the same physical core as the victim; the demonstrated attack recovered RSA-4096 private keys from co-located processes and virtual machines.
The record
- CVE
- CVE-2021-46778
- Published
- Aug 9, 2022
- Updated
- Sep 17, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-203
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 9, 2022CVE publishedPublication date reported by the CVE source.
- Sep 17, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- SQUIP research demonstrationproof of concept · demonstrated
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Technologies
Your stack
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