What’s Vulnerable › Vulnerabilities

CVE-2021-26356

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-05-09 · updated 2026-06-17
• Weakness: CWE-367

Description

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

Affected products

• AMD Epyc 7001 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7002 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7232P Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7251 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7252 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7261 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7262 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7272 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7281 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7282 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 72F3 Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7301 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7302 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7302P Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7313 Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7313P Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7343 Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7351 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7351P Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7352 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7371 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7373X Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7401 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7401P Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h
• AMD Epyc 7402 Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7402P Firmware: before romepi_1.0.0.d — fixed in romepi_1.0.0.d
• AMD Epyc 7413 Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7443 Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7443P Firmware: before milanpi_1.0.0.6 — fixed in milanpi_1.0.0.6
• AMD Epyc 7451 Firmware: before naplespi_1.0.0.h — fixed in naplespi_1.0.0.h

How to fix

Upgrade to a fixed version: AMD Epyc 7001 Firmware naplespi_1.0.0.h; AMD Epyc 7002 Firmware romepi_1.0.0.d; AMD Epyc 7232P Firmware romepi_1.0.0.d; AMD Epyc 7251 Firmware naplespi_1.0.0.h; AMD Epyc 7252 Firmware romepi_1.0.0.d; AMD Epyc 7261 Firmware naplespi_1.0.0.h; AMD Epyc 7262 Firmware romepi_1.0.0.d; AMD Epyc 7272 Firmware romepi_1.0.0.d; AMD Epyc 7281 Firmware naplespi_1.0.0.h; AMD Epyc 7282 Firmware romepi_1.0.0.d; AMD Epyc 72F3 Firmware milanpi_1.0.0.6; AMD Epyc 7301 Firmware naplespi_1.0.0.h. Check the vendor advisory for mitigations.

References

• https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3001
• https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4001
• https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3001
• https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-4001

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