dbcve.org
Epyc 7002 FirmwareOperating system · Amd

CVE-2021-26408

HIGH · 7.1 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 →
73/100
Remediation priority · Elevated
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
Insufficient validation of elliptic curve points in SEV-legacy firmware may compromise SEV-legacy guest migration potentially resulting in loss of guest's integrity or confidentiality.

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 vulnerability exists in AMD SEV-legacy firmware where elliptic curve point validation is insufficient. During VM migration, improper validation of cryptographic points could allow malformed data to be processed, potentially compromising the integrity or confidentiality of SEV-legacy encrypted guests.

MitigationApply AMD-provided SEV-legacy firmware updates that address the elliptic curve validation deficiency. Verify VM migration functionality works correctly after applying the patch.

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 7002 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7001 FirmwareOperating system
Affected:< naplespi-sp3_1.0.0.g
Epyc 7232p FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7252 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7262 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7272 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7282 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
Epyc 7302 FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c

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
None

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

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
    Check /proc/cpuinfo or use `dmidecode -t processor | grep -i 'AMD Epyc'` to confirm the processor is one of the affected models (7001, 7002, 7232p, 7252, 7262, 7272, 7282, or 7302)
    Affected if The processor is an AMD Epyc 7001, 7002, 7232p, 7252, 7262, 7272, 7282, or 7302
  2. Check SEV-legacy firmware version
    Use `openssl` or platform-specific tools to query the SEV firmware version, or check the system management interface (like BIOS/UEFI or IPMI) for the SEV-legacy firmware version string
    Affected if The firmware version is below romepi-sp3_1.0.0.c (for 7002, 7232p, 7252, 7262, 7272, 7282, 7302) or below naplespi-sp3_1.0.0.g (for 7001)
  3. Verify SEV-legacy is enabled
    Check if SEV-legacy is actively configured on the system using `kvm -cpu help` or by inspecting libvirt/qemu configuration files for SEV-legacy VM definitions. Also check `/sys/module/kvm_amd/parameters/sev_lf` if available
    Affected if SEV-legacy is enabled and in use for encrypted virtual machines

The system is affected if it uses an AMD Epyc 7001/7002/7232p/7252/7262/7272/7282/7302 processor with SEV-legacy enabled and firmware version below the specified thresholds.

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 AMD-provided SEV-legacy firmware updates that address the elliptic curve validation deficiency. Verify VM migration functionality works correctly after applying the patch.

Recommended fix High confidence

romepi-sp3_1.0.0.c (Epyc 7002) / naplespi-sp3_1.0.0.g (Epyc 7001)

  1. Obtain the updated SEV-legacy firmware from AMD's support website or through your hardware vendor
  2. For Epyc 7002 series processors (including 7232p, 7252, 7262, 7272, 7282, 7302): upgrade to firmware version romepi-sp3_1.0.0.c or later
  3. For Epyc 7001 series processors (Naples): upgrade to firmware version naplespi-sp3_1.0.0.g or later
  4. Apply the firmware update following AMD's standard firmware update procedures for your specific server platform
  5. Verify the firmware version has been successfully applied after updating

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

Fix this in Epyc 7002 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2021-26408 in production — separate from our analysis above.

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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