Service interruption via BIOS2PSP race condition
Published May 9, 2023 · Updated Jan 28, 2025
TOCTOU in the BIOS2PSP command in AMD AGESA on affected Ryzen and Athlon processors allows attackers to interrupt service during S3 resume. The command checks BIOS-controlled data, then uses it after a race window, causing the ASP bootloader to read beyond SRAM bounds. Exploitation requires a malicious BIOS, a successful race between the check and use, and an S3 resume event; the bounded result is denial of service.
Summary
What happened
TOCTOU in the BIOS2PSP command in AMD AGESA on affected Ryzen and Athlon processors allows attackers to interrupt service during S3 resume. The command checks BIOS-controlled data, then uses it after a race window, causing the ASP bootloader to read beyond SRAM bounds. Exploitation requires a malicious BIOS, a successful race between the check and use, and an S3 resume event; the bounded result is denial of service.
The record
- CVE
- CVE-2021-46792
- Published
- May 9, 2023
- Updated
- Jan 28, 2025
- Vendor
- AMD
- Product
- AMD Ryzen 3000 Series Mobile Processors with Radeon Graphics (Picasso)
- Classifications
- CWE-367, T1499
- Attack vector
- network
- Privileges
- unauthenticated
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
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- Affected versionversion=various
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What is affected?
Attacks
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Weakness, pattern, technique
Public exploit references
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