Integrity loss via HMAC timing attack
Published Jun 26, 2026 · Updated Jun 26, 2026
Observable timing discrepancy in ASP firmware for affected AMD client processors allows local users with high privileges to forge HMAC messages. The ASP exposes response-time differences during hash message authentication code verification, permitting a brute-force attack that accepts arbitrary message input. Exploitation requires high local privileges and a high-complexity timing attack, and successful forgery compromises message integrity.
Summary
What happened
Observable timing discrepancy in ASP firmware for affected AMD client processors allows local users with high privileges to forge HMAC messages. The ASP exposes response-time differences during hash message authentication code verification, permitting a brute-force attack that accepts arbitrary message input. Exploitation requires high local privileges and a high-complexity timing attack, and successful forgery compromises message integrity.
The record
- CVE
- CVE-2023-20572
- Published
- Jun 26, 2026
- Updated
- Jun 26, 2026
- Vendor
- Advanced Micro Devices, Inc.
- Product
- AMD Ryzen™ 7000 Series Desktop Processors
- Classifications
- CWE-208
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Jun 26, 2026CVE publishedPublication date reported by the CVE source.
- Jun 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo