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Epyc 7763 FirmwareOperating system · Amd

CVE-2020-12966

MEDIUM · 5.5 CVSS v3.1 Published 2022-02-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
57/100
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
AMD EPYC™ Processors contain an information disclosure vulnerability in the Secure Encrypted Virtualization with Encrypted State (SEV-ES) and Secure Encrypted Virtualization with Secure Nested Paging (SEV-SNP). A local authenticated attacker could potentially exploit this vulnerability leading to leaking guest data by the malicious hypervisor.

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

AMD EPYC processors contain an information disclosure vulnerability in SEV-ES and SEV-SNP technologies. A local authenticated attacker with hypervisor-level access could potentially exploit this to leak guest virtual machine data that should be protected under SEV encryption mechanisms.

MitigationApply AMD-provided firmware/microcode updates for affected EPYC processors. If unavailable, consider disabling SEV-ES/SEV-SNP for sensitive workloads until patches are available.

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_1.0.0.5
Epyc 7713p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 7713 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 7663 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 7643 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 75f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 7543p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.5
Epyc 7543 FirmwareOperating system
Affected:< milanpi-sp3_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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 AMD EPYC processor model
    Run 'dmidecode -s processor-version' or check '/proc/cpuinfo' for the processor name
    Affected if The processor model is one of: EPYC 7763, EPYC 7713p, EPYC 7713, EPYC 7663, EPYC 7643, EPYC 75f3, EPYC 7543p, or EPYC 7543
  2. Check firmware version
    Run 'dmidecode -s bios-version' or inspect '/sys/class/dmi/id/bios_version' to obtain the firmware/microcode version
    Affected if The firmware version is missing or lower than milanpi-sp3_1.0.0.5 (for the identified EPYC model)
  3. Determine if SEV-ES is enabled
    Check for SEV-ES status in the virtualization environment: run 'virsh domcapabilities' and look for sev-es capability, or inspect '/sys/module/kvm_amd/parameters/sev_es_enabled' if available
    Affected if SEV-ES is active on any virtual machine running on the affected processor and firmware
  4. Determine if SEV-SNP is enabled
    Check for SEV-SNP status via 'cat /sys/module/kvm_parameters/snp' or through hypervisor configuration logs for SEV-SNP VM instances
    Affected if SEV-SNP is active on any virtual machine running on the affected processor and firmware

The environment is affected if an AMD EPYC processor from the listed models is running with firmware version below milanpi-sp3_1.0.0.5 AND has SEV-ES or SEV-SNP encryption enabled for any guest virtual machine.

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 firmware/microcode updates for affected EPYC processors. If unavailable, consider disabling SEV-ES/SEV-SNP for sensitive workloads until patches are available.

Recommended fix High confidence

milanpi-sp3_1.0.0.5

  1. Obtain the updated firmware file (milanpi-sp3_1.0.0.5) from the AMD website or your server vendor's support portal
  2. Verify the firmware is compatible with your specific EPYC processor model and server hardware
  3. Apply the firmware update through your server's BIOS/UEFI interface, BMC/IPMI firmware update utility, or vendor-specific update tool
  4. After updating, verify the new firmware version is correctly installed
  5. Ensure SEV-ES and SEV-SNP features are reconfigured as needed after the firmware update
Caveat Firmware updates may require server downtime and should be tested in a non-production environment first; some vendors may require specific update procedures or tools

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
  • Implementation2.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,080
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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-2020-12966 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