CVE-2020-12926
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 · uneditedThe Trusted Platform Modules (TPM) reference software may not properly track the number of times a failed shutdown happens. This can leave the TPM in a state where confidential key material in the TPM may be able to be compromised. AMD believes that the attack requires physical access of the device because the power must be repeatedly turned on and off. This potential attack may be used to change confidential information, alter executables signed by key material in the TPM, or create a denial of service of the device.
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 confidenceThe Trusted Platform Modules (TPM) reference software fails to properly track the count of failed shutdown events. This allows an attacker with repeated physical access to the device (via power cycling) to place the TPM in a compromised state where confidential key material may be extracted, enabling modification of executables signed by TPM keys or causing device denial of service.
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 dataall versionsCVSS 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
- Physical
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/AC:H/PR:N/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 checksWork through these to decide whether this CVE applies to you.
-
Identify if AMD TPM reference software is in useCheck system hardware inventory or TPM module documentation for 'AMD Trusted Platform Module' or 'AMD TPM' branding. On Linux, run 'ls /dev/tpm*' and check firmware details via 'tpm2_getcap -c properties-fixed'. On Windows, check Device Manager under 'Security devices' for AMD TPM entries.Affected if The system contains an AMD Trusted Platform Module using AMD's reference software implementation.
-
Check TPM firmware versionRetrieve TPM firmware version using platform-specific tools. On Linux: 'tpm2_getcap -c properties-fixed' shows vendor version. On Windows: run 'tpmvctl /ds' or check TPM manufacturer information in Device Manager.Affected if Any AMD TPM firmware version is installed, as all versions of the AMD TPM reference software are affected by this vulnerability.
-
Verify physical access controls existAudit physical security controls: check if system chassis has locking mechanisms, verify tamper-evident seals are in place, review physical access logs for the system location, and assess whether multiple power cycles by unauthorized persons is possible.Affected if Physical access controls are insufficient to prevent an attacker from repeatedly power cycling the device.
-
Check for signs of TPM compromiseReview TPM attestation logs if available. Check for unexpected TPM ownership changes or key migration events. On Linux, examine 'tpm2_getcap -c pcrs' for unexpected PCR modifications. Look for irregularities in TPM-backed key usage.Affected if TPM shows signs of unexpected state changes, key extraction, or ownership modifications consistent with the documented attack vector.
A system is affected if it utilizes AMD Trusted Platform Modules reference software (any version) and lacks sufficient physical access controls to prevent the repeated power-cycling attack required to exploit this flaw.
Generated from the published advisory. Verify against your own configuration.
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 dataApply AMD-provided TPM firmware updates that implement proper shutdown failure tracking, and restrict physical access to affected devices to prevent the required power-cycle attack vector.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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 locallyCheck whether your project pulls in CVE-2020-12926 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-12926 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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.
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.
- 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