Improper Signature VerificationWeakness · CWE-347

CVE-2024-36347

MEDIUM · 6.4 CVSS v3.1 Published 2025-06-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
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 signature verification in AMD CPU ROM microcode patch loader may allow an attacker with local administrator privilege to load malicious microcode, potentially resulting in loss of integrity of x86 instruction execution, loss of confidentiality and integrity of data in x86 CPU privileged context and compromise of SMM execution environment.

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

The AMD CPU ROM microcode patch loader has improper signature verification, allowing a local administrator to load malicious microcode into the CPU. This compromises x86 instruction execution integrity, privileged CPU contexts, and the System Management Mode (SMM) environment.

MitigationApply AMD-provided BIOS/firmware microcode updates that implement proper cryptographic signature verification. Restrict administrative privileges and monitor for unauthorized microcode loading until patches are deployed.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
High
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:H/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 AMD processor in system
    Run 'wmic cpu get Name,Manufacturer,ProcessorId' or check /proc/cpuinfo on Linux for 'AuthenticAMD' in the vendor field
    Affected if System does not have an AMD CPU, the vulnerability does not apply
  2. Check current microcode version loaded
    On Linux, read /proc/cpuinfo for 'microcode' version, or use 'cpuid' tool. On Windows, use 'wmic bios get smbiosbiosversion' or check Event Viewer for microcode loading events
    Affected if Microcode version cannot be determined or is significantly outdated compared to AMD's latest microcode releases for that CPU model
  3. Verify BIOS/UEFI settings for microcode loading
    Enter system BIOS/UEFI setup and check for options related to 'microcode update', 'CPU firmware update', or 'ROM patch' loading. Check if 'secure boot' or signature verification options are enabled or disabled
    Affected if BIOS settings allow loading unsigned microcode or have disabled signature verification for CPU microcode updates
  4. Check for administrative privilege abuse indicators
    Review system event logs (Windows Event Viewer under Application/System logs, or Linux audit logs under /var/log/audit/) for events indicating unauthorized microcode loading, unexpected CPU firmware updates, or execution of tools that interact with CPU microcode (e.g., AMDs loadmocm, msrtools)
    Affected if Logs show microcode loading activity performed by unexpected accounts or outside of normal OS boot sequences

A system is affected if it runs on an AMD CPU with microcode that lacks proper cryptographic signature verification in the ROM patch loader, allowing a local administrator to load arbitrary microcode.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply AMD-provided BIOS/firmware microcode updates that implement proper cryptographic signature verification. Restrict administrative privileges and monitor for unauthorized microcode loading until patches are deployed.

Have this fixed 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
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Scan for this in your stack

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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-2024-36347 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
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  • Version or environment caveats, and links to real fixes
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