dbcve.org
Epyc 7203 FirmwareOperating system · Amd

CVE-2021-26344

HIGH · 8.2 CVSS v3.1 Published 2024-08-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
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
An out of bounds memory write when processing the AMD PSP1 Configuration Block (APCB) could allow an attacker with access the ability to modify the BIOS image, and the ability to sign the resulting image, to potentially modify the APCB block resulting in arbitrary code execution.

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 · moderate confidence

Memory corruption vulnerability in AMD's Platform Security Processor (PSP) firmware where parsing the APCB configuration block triggers an out-of-bounds write, allowing arbitrary code execution in the PSP trusted execution environment.

MitigationApply vendor-supplied BIOS/firmware updates addressing this vulnerability; restrict physical access and signing key availability to prevent unauthorized BIOS modification.

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 7203 FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7203p FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 72f3 FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7303 FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7303p FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7313 FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7313p FirmwareOperating system
Affected:< milanpi_1.0.0.5
Epyc 7343 FirmwareOperating system
Affected:< milanpi_1.0.0.5

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
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/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 -s processor-family' or check system documentation to confirm the exact Epyc model number (e.g., 7203, 7203p, 72f3, 7303, 7303p, 7313, 7313p, or 7343)
    Affected if The processor model is one of: 7203, 7203p, 72f3, 7303, 7303p, 7313, 7313p, or 7343
  2. Retrieve the PSP firmware version
    Use AMD-provided tools such as 'amd_psp' or check the system BIOS/UEFI information page for the PSP or milanpi firmware version string
    Affected if The displayed firmware version is not available or shows a version string different from milanpi_1.0.0.5
  3. Compare firmware version against the affected range
    If a milanpi firmware version is visible, compare it to the vulnerable threshold: versions earlier than milanpi_1.0.0.5 are affected
    Affected if The installed milanpi firmware version is less than milanpi_1.0.0.5 (for example, milanpi_1.0.0.4 or earlier)
  4. Verify BIOS signing key integrity
    Review system logs or use vendor tools to confirm no unauthorized modifications to the BIOS image or signing certificates have occurred
    Affected if Signs of tampering or unauthorized BIOS modifications are detected

A system is affected if it uses any of the listed AMD Epyc models (7203 through 7343 variants) with milanpi firmware version earlier than milanpi_1.0.0.5, and an attacker has capability to modify and sign a malicious BIOS image.

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 addressing this vulnerability; restrict physical access and signing key availability to prevent unauthorized BIOS modification.

Recommended fix High confidence

milanpi_1.0.0.5 or later PSP firmware (contact server vendor for exact BIOS version)

  1. 1. Identify the server vendor for the AMD Epyc system (e.g., Dell, HPE, Lenovo, Supermicro, etc.)
  2. 2. Visit the vendor's support or download page for the specific server model
  3. 3. Locate and download the latest BIOS/firmware update that includes the milanpi_1.0.0.5 or later PSP firmware
  4. 4. Follow the vendor's documented firmware update process, which typically involves: running the provided update utility, rebooting the server, and allowing the update to complete without interruption
  5. 5. Verify the installed firmware version post-update to confirm the patch has been applied
Caveat Firmware updates carry risk of system inaccessibility if interrupted; ensure stable power and follow vendor procedures exactly

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

Fix this in Epyc 7203 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,150
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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-2021-26344 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

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