Cyber Resilience

CVE-2021-26320

Medium

Published: 16 November 2021

Published
16 November 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0010 28.0th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-26320 is a medium-severity Improper Certificate Validation (CWE-295) vulnerability in Amd Epyc 7601 Firmware. Its CVSS base score is 5.5 (Medium).

Operationally, ranked at the 28.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Insufficient validation of the AMD SEV Signing Key (ASK) in the SEND_START command in the SEV Firmware may allow a local authenticated attacker to perform a denial of service of the PSP

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

amd
epyc 7601 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7551p firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7551 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7501 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7451 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7401 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7371 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7351p firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7351 firmware
≤ naplespi-sp3_1.0.0.g
amd
epyc 7301 firmware
≤ naplespi-sp3_1.0.0.g
+47 more product configuration(s) — see NVD for full list

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-295

When certificates are used to establish component provenance, the control requires correct certificate validation procedures.

addresses: CWE-295

Mandates approved trust anchors and issuance policies, directly preventing acceptance of unvalidated or untrusted certificates.

addresses: CWE-295

Correct system time is required for proper enforcement of certificate notBefore/notAfter dates and time-based revocation checks.

References