Local ASP memory disclosure via SHA256 syscall
Published May 9, 2023 · Updated Jan 28, 2025
Information disclosure in AMD processor bootloaders allows local users to expose ASP memory through a SHA256 system call. A compromised or malicious AMD Boot Loader or user application can invoke the call, but AMD has not disclosed the validation or memory-handling defect that returns protected ASP contents to userspace. Reachability requires low-privilege local access and control of an ABL or UApp; the published impact is limited to confidentiality.
Summary
What happened
Information disclosure in AMD processor bootloaders allows local users to expose ASP memory through a SHA256 system call. A compromised or malicious AMD Boot Loader or user application can invoke the call, but AMD has not disclosed the validation or memory-handling defect that returns protected ASP contents to userspace. Reachability requires low-privilege local access and control of an ABL or UApp; the published impact is limited to confidentiality.
The record
- CVE
- CVE-2021-26371
- Published
- May 9, 2023
- Updated
- Jan 28, 2025
- Vendor
- Advanced Micro Devices, Inc.
- Product
- 3rd Gen AMD EPYC Processors
- Classifications
- T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 9, 2023CVE publishedPublication date reported by the CVE source.
- Jan 28, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=various
What conditions does exploitation require?
What is affected?
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.
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Technologies
Your stack
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Your stack
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