CVE-2020-12355
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 · uneditedAuthentication bypass by capture-replay in RPMB protocol message authentication subsystem in Intel(R) TXE versions before 4.0.30 may allow an unauthenticated user to potentially enable escalation of privilege via physical access.
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 confidenceThis is an authentication bypass vulnerability in Intel TXE (Trusted Execution Engine) firmware's RPMB (Replay Protected Memory Block) protocol message authentication subsystem. The vulnerability allows an unauthenticated user with physical access to capture and replay RPMB messages, bypassing authentication and potentially achieving privilege escalation.
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< 4.0.30CVSS 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
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/AC:L/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.
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Identify if Intel TXE firmware is presentCheck system documentation or BIOS/UEFI information for Intel Trusted Execution Engine (TXE) firmware. Intel TXE is typically found on Intel NUCs, some server motherboards, and embedded systems with Intel processors.Affected if System has Intel TXE firmware installed
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Determine Intel TXE firmware versionAccess the Intel TXE firmware version through BIOS/UEFI settings, Intel firmware update utilities, or system management interfaces that report firmware versions. Compare the installed version against the affected range.Affected if Installed Intel TXE firmware version is less than 4.0.30
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Verify RPMB subsystem is in useDetermine whether the system uses RPMB (Replay Protected Memory Block) functionality. This is typically associated with eMMC storage or secure storage implementations that rely on Intel TXE for secure message handling.Affected if RPMB is enabled or accessible on the system
System is affected if it contains Intel TXE firmware version earlier than 4.0.30 and utilizes the RPMB subsystem for secure storage operations.
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 data4.0.30
Update Intel TXE firmware to version 4.0.30 or later to obtain the patch. Implement physical security controls to restrict access to affected hardware.
- Consultation6.0 h
- Implementation12.0 h
- Testing10.0 h
- Review / QA6.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-12355 — 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-2020-12355 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
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- 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
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