CVE-2021-0091
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 · uneditedImproper access control in the firmware for some Intel(R) Processors may allow an unauthenticated user to potentially enable an escalation of privilege via local 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 confidenceImproper access control in Intel processor firmware allows an unauthenticated local user to potentially escalate privileges. This is a firmware-level vulnerability where the access control mechanism fails to properly restrict certain operations, enabling a local attacker to gain elevated access.
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 versionsall versionsall versionsall versionsall versionsall versionsall versionsall 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 the processor modelRun 'dmidecode -s processor-version' or check system information via 'msinfo32' on Windows or 'lscpu' on Linux to determine the exact CPU modelAffected if The processor is not one of the listed Intel Atom C3308, C3336, C3338, C3338r, C3436l, C3508, C3538, or C3558 models, then the system is not affected by this specific CVE
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Verify the affected processor is presentCompare the identified processor model against the CVE-affected product list: Intel Atom C3308, C3336, C3338, C3338r, C3436l, C3508, C3538, C3558Affected if If the installed processor matches any of these eight models, the system falls within the scope of this vulnerability
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Determine the current firmware versionAccess the system BIOS/UEFI setup during boot, or use tools like 'dmidecode -s bios-version' on Linux, 'wmic bios get smbiosbiosversion' on Windows, or Intel's System Management Software to read the current firmware versionAffected if If the processor is one of the affected models and the firmware version has not been updated to address CVE-2021-0091, the system remains vulnerable
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Check for available firmware updatesConsult Intel's security advisory for this CVE and compare the installed firmware version against the patched version provided in Intel's documentation, or contact the system manufacturer for firmware update statusAffected if If no firmware update has been applied to address this access control vulnerability, the improper access control flaw is still present
A system is affected if it contains any of the Intel Atom C3308, C3336, C3338, C3338r, C3436l, C3508, C3538, or C3558 processors and the BIOS/UEFI firmware has not been updated to the patched version released for CVE-2021-0091.
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 Intel processor firmware updates (BIOS/UEFI updates) provided through Intel's security advisory. Verify that systems are running patched firmware versions.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0091 — 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-2021-0091 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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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
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