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Vulnerability record · CVE-2023-20521 · published 14 November 2023

CVE-2023-20521: Amd epyc 7001 firmware toctou race condition vulnerability

AAmd · Epyc 7001 Firmware

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.

5.7 CVSS 3.1 Medium EPSS 0.26% · top 84.0% CWE-367 · TOCTOU race condition
5.7CVSS 3.1 base score
0.26%EPSS exploitation probability, 30 days
NoNot in CISA KEV
93Affected product versions listed by NVD
6References
17 Jun 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

93 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3002 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4002 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-5001
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3002 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4002 Vendor Advisory
https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-5001

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2023-20521), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.