CVE intelligence and bounded remediation

CVE-2023-20521 — Amd Epyc 7001 Firmware security vulnerability

Medium CVSS 5.7

TOCTOU in the ASP Bootloader may allow an attacker with physical access to tamper with SPI ROM records after memory content verification, potentially leading to loss of confidentiality or a denial of service.

Severity
Medium
CVSS
5.7 (3.1)
Published
2023-11-14
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-367

Affected products

  • amd / epyc_7001_firmware
  • amd / epyc_7251_firmware
  • amd / epyc_7261_firmware
  • amd / epyc_7281_firmware
  • amd / epyc_7301_firmware
  • amd / epyc_7351_firmware

Showing 6 representative product identities from 93 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Race condition, TOCTOU, and lifecycle synchronization

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Check exposure

  • Map concurrent actors, shared state, lock boundaries, signals, callbacks, retries, and check-then-use sequences in the affected path.
  • Determine whether untrusted users can influence timing, object names, filesystem state, or repeated state transitions.
  • Identify clustered and multi-process behavior that repository-local tests may not represent.

Remediate safely

  • Make the sensitive state transition atomic or protect it with a consistently ordered synchronization primitive.
  • Perform authorization and invariant checks on the same authoritative object and transaction used for the operation.
  • Use unique private resources, safe ownership transfer, and idempotent operations; add deterministic concurrency regression tests.

Authoritative sources

Complete CVE record and remediation plan

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