CVE-2021-3452
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 · uneditedA potential vulnerability in the system shutdown SMI callback function in some ThinkPad models may allow an attacker with local access and elevated privileges to execute arbitrary code.
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 confidenceThis is a firmware-level vulnerability in the system shutdown SMI (System Management Interrupt) callback function affecting certain ThinkPad laptops. The SMI callback runs in System Management Mode (SMM), a high-privilege CPU mode. An attacker with local access and existing elevated privileges can exploit this to execute arbitrary code in the SMM context, bypassing standard OS security controls.
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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/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 checksWork through these to decide whether this CVE applies to you.
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Identify system model and manufacturerRun 'wmic computersystem get model,manufacturer' or check the system information during boot (press Enter on startup screen). Look for ThinkPad model name/number.Affected if The system is a Lenovo ThinkPad laptop; non-ThinkPad models are not affected by this specific SMI vulnerability.
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Retrieve BIOS versionRun 'wmic bios get smbiosbiosversion' or check BIOS setup (press F1 on startup). Record the BIOS version string.Affected if Any Lenovo ThinkPad with a BIOS version that predates the vendor patch is potentially affected. Compare against Lenovo's published fixed BIOS version for your specific model.
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Verify SMM write protection statusAccess BIOS setup (F1 at startup) and locate 'Security' or 'SMM' settings. Check if 'SMM Feature Protection' or 'SMM Write Protection' is disabled or unavailable. This can indicate vulnerability exposure.Affected if SMM write protection is disabled or not available on the ThinkPad, making the SMI callback potentially exploitable.
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Check for existing SMM vulnerability indicatorsUse tools like 'chipsEC' or 'uefi-firmware-parser' (if available) to dump and analyze the BIOS image. Look for modifications in the shutdown SMI handler (SMI #A7 or shutdown-related handlers).Affected if The shutdown SMI handler shows signs of modification, missing protection, or unpatched code flow.
A user is affected if they own a Lenovo ThinkPad with a BIOS version earlier than Lenovo's patched version, and the SMM write protection is not enabled in BIOS settings.
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 the vendor-supplied BIOS/firmware update from Lenovo for affected ThinkPad models. Prioritize systems with direct physical access in high-security environments.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-3452 — 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-2021-3452 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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- Version or environment caveats, and links to real fixes
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