dbcve.org
Epyc 7003 FirmwareOperating system · Amd

CVE-2021-26404

MEDIUM · 5.5 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 →
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
Improper input validation and bounds checking in SEV firmware may leak scratch buffer bytes leading to potential information disclosure.

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

Improper input validation and bounds checking in AMD SEV (Secure Encrypted Virtualization) firmware allows a potential information disclosure through leakage of scratch buffer bytes. This memory handling flaw in the firmware could expose sensitive data from previously used memory regions.

MitigationApply the AMD SEV firmware update released to address this vulnerability. Organizations should verify their SEV firmware version and coordinate with AMD or their cloud provider for patch deployment.

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 7003 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7313 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7313p FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7343 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7373x FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 73f3 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7413 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9
Epyc 7443 FirmwareOperating system
Affected:< milanpi-sp3_1.0.0.9

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 7003 series processor in use
    Run 'dmidecode -t processor | grep -i AMD' or 'lscpu | grep -i AMD' to confirm the processor model is one of the affected Epyc 7003 variants (7313, 7313p, 7343, 7373x, 73f3, 7413, 7443, or other 7003 series)
    Affected if The system does not have an AMD Epyc 7003 series processor, the vulnerability does not apply
  2. Verify AMD SEV is enabled in the system
    Check the hypervisor or host configuration for SEV support - on Linux hosts, inspect /sys/module/kvm_amd/parameters/sev or use 'cat /proc/cpuinfo | grep sev' to confirm SEV is active and configured
    Affected if SEV is not enabled or not present on the system, the vulnerability does not apply
  3. Obtain the SEV firmware version
    Use AMD SEV platform diagnostic tools such as 'sevtool --platform_status' or check via the hypervisor (e.g., 'virsh domcapabilities' for libvirt/KVM) to retrieve the current SEV firmware version string
    Affected if SEV firmware version cannot be retrieved or is not available, further manual verification via BIOS/UEFI or AMD tooling may be required
  4. Compare firmware version against the affected threshold
    Compare the obtained SEV firmware version to 'milanpi-sp3_1.0.0.9' - versions lower than this string are affected (e.g., milanpi-sp3_1.0.0.8, milanpi-sp3_1.0.0.5, etc.)
    Affected if The installed SEV firmware version is less than milanpi-sp3_1.0.0.9, the system is affected by this vulnerability

The system is affected only if it runs an AMD Epyc 7003 series processor with SEV enabled and the SEV firmware version is below milanpi-sp3_1.0.0.9.

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 AMD SEV firmware update released to address this vulnerability. Organizations should verify their SEV firmware version and coordinate with AMD or their cloud provider for patch deployment.

Recommended fix High confidence

milanpi-sp3_1.0.0.9 or later

  1. Identify the current firmware version of the AMD Epyc 7003 processor system using BMC/IPMI or system information tools
  2. Download the updated SEV firmware (milanpi-sp3_1.0.0.9 or later) from the official AMD website at www.amd.com
  3. Apply the firmware update through the system's BMC (Baseboard Management Controller) or BIOS update mechanism, following AMD's documented firmware update procedures
  4. After updating, verify the firmware has been applied successfully and the system is functioning normally
Caveat Firmware updates carry inherent risks and should be performed with appropriate backups and during a planned maintenance window

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

Fix this in Epyc 7003 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-26404 — 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-2021-26404 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