CVE-2021-21574
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 · uneditedDell BIOSConnect feature contains a buffer overflow vulnerability. An authenticated malicious admin user with local access to the system may potentially exploit this vulnerability to run arbitrary code and bypass UEFI restrictions.
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 confidenceDell BIOSConnect feature contains a buffer overflow vulnerability. An authenticated malicious admin user with local physical access to the system can exploit this to run arbitrary code and bypass UEFI security restrictions, potentially achieving code execution at the firmware level.
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< 1.3.3< 1.4.1< 1.4.1< 1.4.0< 1.3.3<= 1.9.0< 1.9.0< 1.9.0CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/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 your Dell system modelRun 'wmic computersystem get model' on Windows or 'dmidecode -s system-product-name' on Linux to get the exact model nameAffected if The model is not one of: Alienware M15 R6, Chengming 3990, Chengming 3991, G15 5510, G15 5511, G3 3500, G5 5500, or G7 7500 (unaffected)
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Check the installed BIOS firmware versionRun 'wmic bios get smbiosbiosversion' on Windows or 'dmidecode -s bios-version' on Linux to retrieve the current BIOS versionAffected if For Alienware M15 R6: version < 1.3.3; Chengming 3990/3991: version < 1.4.1; G15 5510: version < 1.4.0; G15 5511: version < 1.3.3; G3 3500: version <= 1.9.0; G5 5500 or G7 7500: version < 1.9.0 (affected)
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Determine if BIOSConnect feature is enabledEnter BIOS setup (press F2 at boot), navigate to BIOS Connect or BIOS Management settings, and check if the feature is turned on. On Windows, use Dell Command | Configure to query BIOS configuration via 'cctk --biosconnect' or check registry under HKLM\SYSTEM\CurrentControlSet\Services\BIOSConnectAffected if BIOSConnect is enabled and the system model and version match the affected ranges above
You are affected if you run one of the listed Dell models with a BIOS version below the specified threshold and have BIOSConnect enabled in the firmware 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 data1.3.31.4.01.4.1
Apply Dell BIOS/firmware updates when available from Dell support. Until patched, minimize physical access to systems and restrict administrative privileges to trusted personnel only.
- Consultation2.0 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 $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21574 — 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-2021-21574 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
- No spam, self-promotion, credentials, or personal data