dbcve.org
Epyc 7h12 FirmwareOperating system · Amd

CVE-2021-26316

HIGH · 7.8 CVSS v3.1 Published 2023-01-11
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 the communication buffer and communication service in the BIOS may allow an attacker to tamper with the buffer resulting in potential SMM (System Management Mode) 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

This is a BIOS firmware vulnerability where the communication buffer and communication service in the BIOS fail to perform proper input validation. An attacker who can access the system (likely with physical access or privileged access) can tamper with the communication buffer, potentially achieving arbitrary code execution in System Management Mode (SMM), which runs at the highest privilege level on x86 processors.

MitigationApply the vendor-provided BIOS/firmware update that addresses this buffer validation issue. Verify that SMM configuration is hardened according to vendor guidance and industry best practices.

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 7h12 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7f72 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7f52 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7f32 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7742 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7702p FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7702 FirmwareOperating system
Affected:< romepi_1.0.0.d
Epyc 7662 FirmwareOperating system
Affected:< romepi_1.0.0.d

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. Check the current BIOS firmware version
    Run `dmidecode -s bios-version` or access the BMC/IPMI interface (e.g., `ipmitool -I lanplus -H <bmc_ip> -U admin -P password raw ...` or via web UI) to retrieve the BIOS firmware version. On some systems, check `/sys/class/dmi/id/bios_version` or use vendor tools like `amd-atl` or platform-specific utilities.
    Affected if The displayed firmware version is earlier than romepi_1.0.0.d and matches an affected model (Epyc 7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, or 7662).
  2. Identify the exact Epyc processor model
    Run `lscpu | grep 'Model name'` or check `/proc/cpuinfo` to confirm the processor is an AMD Epyc model from the affected list.
    Affected if The processor is an AMD Epyc 7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, or 7662.
  3. Verify SMM communication interface status
    Check the BIOS configuration for SMM-related settings. On AMD Epyc systems, this may be accessible via the BMC (e.g., using IPMI `raw` commands or through the BIOS setup under 'Advanced' > 'SMM' or similar). Look for settings related to 'SMM Communication Buffer' or 'BIOS Communication'.
    Affected if The SMM communication buffer interface is present and enabled on the system.
  4. Check for vendor firmware update availability
    Consult the AMD Epyc vendor (e.g., your server manufacturer) support portal or release notes for the specific Epyc model to confirm if a firmware update to romepi_1.0.0.d or later is available.
    Affected if A newer firmware version (romepi_1.0.0.d or later) is available but not yet applied.

You are affected if your system has an AMD Epyc processor from the listed models and runs firmware versions earlier than romepi_1.0.0.d with the SMM communication buffer interface enabled.

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 the vendor-provided BIOS/firmware update that addresses this buffer validation issue. Verify that SMM configuration is hardened according to vendor guidance and industry best practices.

Recommended fix High confidence

romepi_1.0.0.d

  1. 1. Identify the current BIOS/firmware version of the AMD Epyc processor by accessing the system BIOS setup or using BMC/IPMI utilities
  2. 2. Navigate to www.amd.com and locate the security advisory for CVE-2021-26316 to obtain the official firmware update package
  3. 3. Download the firmware update package specifically for your Epyc model (7h12, 7f72, 7f52, 7f32, 7742, 7702p, 7702, or 7662)
  4. 4. Apply the firmware update using the appropriate method for your system: either through BIOS flash utility, BMC firmware update interface, or AMD's firmware update tools
  5. 5. Reboot the system and verify the BIOS/firmware has been updated to version romepi_1.0.0.d or later
  6. 6. Confirm the security vulnerability is resolved by reviewing the BIOS version in the system information
Caveat BIOS/firmware updates carry inherent risk of system unavailability if interrupted; ensure stable power and follow vendor update procedures precisely

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

Fix this in Epyc 7h12 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-26316 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-26316 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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