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Epyc 7763 FirmwareOperating system · Amd

CVE-2021-26353

HIGH · 7.8 CVSS v3.1 Published 2022-05-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Failure to validate inputs in SMM may allow an attacker to create a mishandled error leaving the DRTM UApp in a partially initialized state potentially resulting in loss of memory integrity.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a System Management Mode (SMM) vulnerability in AMD processors where input validation failures allow an attacker to create a mishandled error condition. This leaves the DRTM (Dynamic Root of Trust Measurement) UApp in a partially initialized state, compromising memory integrity protections.

MitigationApply vendor-supplied BIOS/firmware updates from AMD and system manufacturers. This is a firmware-level issue requiring SMM/UEFI updates rather than software patches.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Epyc 7763 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7713p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7713 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7663 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7643 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 75f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7543p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4
Epyc 7543 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the AMD Epyc processor model
    Run `dmidecode -t processor | grep -E 'Version|Model'` or `lscpu | grep 'Model name'` to retrieve the processor model information
    Affected if The processor model matches one of the affected variants: Epyc 7763, 7713p, 7713, 7663, 7643, 75f3, 7543p, or 7543
  2. Check the system firmware version
    Run `dmidecode -s bios-version` or access the BMC/IPMI interface to retrieve the current BIOS/firmware version for the AMD Epyc system
    Affected if The firmware version is present and is earlier than milanpi-sp3_1.0.0.4 (for example, 1.0.0.3 or any version below 1.0.0.4)
  3. Verify if DRTM is enabled on the system
    Check the BIOS/UEFI settings for DRTM (Dynamic Root of Trust Measurement) or use OS-level tools such as `tpm2_getcap -c pcrs` to inspect TPM-related configurations; consult system documentation for DRTM status
    Affected if DRTM is enabled and the system uses the DRTM UApp functionality, as the vulnerability affects the partially initialized state of DRTM

A system is affected if it runs one of the listed AMD Epyc processor models with firmware versions below milanpi-sp3_1.0.0.4 and has DRTM enabled, which leaves the DRTM UApp vulnerable to the input validation flaw.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor-supplied BIOS/firmware updates from AMD and system manufacturers. This is a firmware-level issue requiring SMM/UEFI updates rather than software patches.

Recommended fix Moderate confidence

milanpi-sp3_1.0.0.4 or later

  1. 1. Identify the exact AMD Epyc processor model(s) in your system from the affected list (7763, 7713p, 7713, 7663, 7643, 75f3, 7543p, 7543)
  2. 2. Determine the current firmware version installed on the affected processor(s)
  3. 3. Navigate to www.amd.com and locate the AMD Epyc 7000 series (Milan) firmware download page
  4. 4. Download the firmware update package milanpi-sp3_1.0.0.4 or later version for your specific processor model
  5. 5. Review the firmware update documentation and release notes for any specific installation requirements
  6. 6. Apply the firmware update following AMD's recommended procedures, which typically involves using the AMD firmware update utility or through system BIOS/UEFI update mechanisms
  7. 7. After update completion, verify the firmware version has been successfully updated to milanpi-sp3_1.0.0.4 or later
  8. 8. Confirm the DRTM UApp initialization completes properly after the update
Caveat Firmware updates carry inherent risk; ensure proper power backup and follow AMD update procedures to avoid system instability

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Epyc 7763 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-26353 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data