CVE-2021-36343
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 BIOS contains an improper input validation vulnerability. A local authenticated malicious user may potentially exploit this vulnerability by using an SMI to gain arbitrary code execution in SMRAM.
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 confidenceDell BIOS contains an improper input validation vulnerability in the System Management Interrupt (SMI) handler. A local authenticated user with privileges to trigger SMIs can exploit this to achieve arbitrary code execution in System Management RAM (SMRAM), which operates at the highest privilege level outside of normal OS control.
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< 2.12.1< 1.24.3< 1.22.0< 1.18.2< 1.15.1< 1.10.1< 1.5.0< 1.24.3CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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 the Dell Precision modelRun `dmidecode -s system-product-name` on Linux or check System Information on Windows to confirm the exact model (e.g., Precision 5820 Tower, Precision 7510).Affected if The system model matches one of the affected models: 5820 Tower, 7510, 7520, 7530, 7540, 7550, 7560, or 7710.
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Check the installed BIOS firmware versionRun `dmidecode -s bios-version` on Linux, or on Windows run `wmic bios get smbiosbiosversion` or check the BIOS setup screen under the Main or Information tab.Affected if The installed version is lower than the threshold for your model: 5820 Tower < 2.12.1, 7510 < 1.24.3, 7520 < 1.22.0, 7530 < 1.18.2, 7540 < 1.15.1, 7550 < 1.10.1, 7560 < 1.5.0, 7710 < 1.24.3.
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Confirm local authenticated access with SMI privilegesVerify the user account has administrative or root privileges on the local system. On Linux check `id` or sudo access; on Windows check if the account is in the Administrators group or has equivalent rights.Affected if The user has local administrator or root privileges that allow triggering System Management Interrupts.
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Verify SMBios presence for SMI handlerRun `dmidecode` and search for SMM (System Management Mode) or SMI-related entries in the BIOS information, or verify that System Management Mode is active via `rdmsr 0xC2` (requires root).Affected if The system exposes an SMI handler and the user can access or trigger SMI events.
A system is affected if it is a Dell Precision model listed above, runs a BIOS firmware version below the specified threshold, and the user has local administrative privileges that enable triggering SMIs.
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.
dbcve · scoped1.5.01.10.11.15.1
Apply the Dell BIOS update provided by the vendor to patch the input validation vulnerability. Organizations should identify affected Dell systems and deploy the firmware update through their enterprise patch management or BIOS update deployment tools.
BIOS firmware version 2.12.1 (5820), 1.24.3 (7510/7710), 1.22.0 (7520), 1.18.2 (7530), 1.15.1 (7540), 1.10.1 (7550), or 1.5.0 (7560) - depending on model
- 1. Identify the exact Dell Precision model from the affected list (5820, 7510, 7520, 7530, 7540, 7550, 7560, or 7710)
- 2. Determine the current BIOS/firmware version installed on the system
- 3. Download the corresponding BIOS update from Dell's support website (www.dell.com) for the specific model
- 4. For each model, apply the minimum fixed version: Precision 5820 Tower: >= 2.12.1, Precision 7510: >= 1.24.3, Precision 7520: >= 1.22.0, Precision 7530: >= 1.18.2, Precision 7540: >= 1.15.1, Precision 7550: >= 1.10.1, Precision 7560: >= 1.5.0, Precision 7710: >= 1.24.3
- 5. Run the BIOS update executable or use Dell Update utility while the system is plugged into AC power
- 6. Allow the firmware update to complete - do not interrupt or power off the system during the flash process
- 7. After reboot, verify the BIOS version has been updated to the fixed release
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-36343 — 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-2021-36343 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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