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Epyc 7232p FirmwareOperating system · Amd

CVE-2021-26323

HIGH · 7.8 CVSS v3.1 Published 2021-11-16
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 SEV Commands while SNP is active may result in a potential impact to 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 · moderate confidence

This AMD vulnerability allows improper SEV (Secure Encrypted Virtualization) command validation when SNP (Secure Nested Paging) is active, potentially compromising memory integrity. The flaw exists in the hardware/firmware layer of AMD processors and could allow attackers to manipulate memory protection mechanisms in virtualized environments using SEV-SNP.

MitigationApply AMD-provided firmware/microcode updates and ensure hypervisor (e.g., SEV-capable KVM, Hyper-V) is updated to versions that enforce proper command validation with SNP enabled; consider disabling SEV-SNP in high-security contexts if updates are unavailable.

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 7232p FirmwareOperating system
Affected:< romepi-sp3_1.0.0.c
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

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 -s processor-version' or 'cat /proc/cpuinfo | grep 'model name'' to identify the CPU. Compare the model number against the list: 7232p, 7763, 7713p, 7713, 7663, 7643, 75f3, 7543p.
    Affected if The processor is one of the listed affected Epyc models.
  2. Check the system firmware version
    Run 'dmidecode -s bios-version' or use vendor-specific tools (e.g., AMD's firmware update utility) to retrieve the current firmware version string.
    Affected if The firmware version is below romepi-sp3_1.0.0.c (for Epyc 7232p) or below milanpi-sp3_1.0.0.4 (for all Milan-based models).
  3. Determine if SEV-SNP is enabled in the hypervisor
    On the host, check for SEV-SNP support via 'cat /sys/module/kvm_amd/parameters/sev_snp' or by querying the hypervisor's SEV capabilities. In a guest VM, inspect CPU flags for 'sev_es' or check via 'virt-host-validate'.
    Affected if SEV-SNP is actively enabled and in use by virtual machines on the host.
  4. Verify SEV-SNP active status in running VMs
    For each running VM, query the hypervisor (e.g., 'virsh domcapabilities' or Hyper-V VM configuration) to confirm that SEV-SNP is configured for that guest.
    Affected if Any VM is running with SEV-SNP enabled on an affected processor with vulnerable firmware.

You are affected if you run any VM with SEV-SNP enabled on an AMD Epyc 7232p, 7763, 7713p, 7713, 7663, 7643, 75f3, or 7543p processor with firmware versions 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 firmware/microcode updates and ensure hypervisor (e.g., SEV-capable KVM, Hyper-V) is updated to versions that enforce proper command validation with SNP enabled; consider disabling SEV-SNP in high-security contexts if updates are unavailable.

Recommended fix High confidence

Firmware version romepi-sp3_1.0.0.c (Epyc 7232p) or milanpi-sp3_1.0.0.4 (all Milan-based Epyc models)

  1. 1. Identify the exact AMD Epyc processor model in your system using tools like 'dmidecode' or BIOS information.
  2. 2. Determine the current firmware version installed on the system by checking the AMD SEV firmware/BIOS settings or using platform-specific tools.
  3. 3. Download the latest AMD Epyc firmware update from the official AMD website (www.amd.com) or your server manufacturer's support page.
  4. 4. Apply the firmware update following the vendor's instructions - this typically involves flashing the new firmware via BIOS update, BMC/IPMI, or vendor-specific update utilities.
  5. 5. After updating, verify the firmware version matches or exceeds the fixed release: romepi-sp3_1.0.0.c for Epyc 7232p, or milanpi-sp3_1.0.0.4 for all Milan-based Epyc processors (7763, 7713, 7713p, 7663, 7643, 75f3, 7543p).
  6. 6. If SNP (Secure Nested Paging) is in use, confirm the update was applied successfully and re-verify SEV command validation is functioning correctly.
Caveat Firmware updates may require server downtime and should be tested in a staging environment before production deployment; verify compatibility with your hypervisor and virtualization stack.

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

Fix this in Epyc 7232p Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
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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-2021-26323 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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