CVE-2021-33086
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 · uneditedOut-of-bounds write in firmware for some Intel(R) NUCs may allow an authenticated user to potentially enable denial of service 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 · moderate confidenceThis is an out-of-bounds write vulnerability in the firmware of certain Intel NUC (Next Unit of Computing) devices. An authenticated user with local access can trigger an out-of-bounds memory write, leading to denial of service. The vulnerability stems from improper bounds checking in firmware code, allowing writes beyond allocated memory regions.
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< bctgl357.0064< bctgl357.0064< ebtgl357.0056< ebtgl357.0056< ebtgl357.0056< ebtgl357.0056< patgl357.0040< patgl357.0040CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 Intel NUC modelCheck the product label on the device chassis or use system information tools (such as dmidecode or the Intel NUC Software Studio) to confirm the exact model number matches one of the affected products: Lapbc510, Lapbc710, Cm11ebc4w, Cm11ebi38w, Cm11ebi58w, Cm11ebi716w, Nuc11pahi3, or Nuc11pahi5Affected if The model number does not match any of the eight listed affected products, then this CVE does not apply
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Determine current firmware versionEnter the BIOS setup by pressing F2 during startup, then navigate to the 'Main' or 'Information' tab to view the firmware version, or use the Intel Firmware Update tool or 'dmidecode -s bios-version' from LinuxAffected if Unable to retrieve firmware version (firmware may be corrupted or inaccessible)
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Compare firmware version to fixed releasesMatch your firmware version string (e.g., bctgl357.xxxx, ebtgl357.xxxx, patgl357.xxxx) against the minimum fixed version for your specific model: Lapbc510/Lapbc710 require bctgl357.0064 or higher; Cm11ebc4w/Cm11ebi38w/Cm11ebi58w/Cm11ebi716w require ebtgl357.0056 or higher; Nuc11pahi3/Nuc11pahi5 require patgl357.0040 or higherAffected if Your installed firmware version is LOWER than the required fixed version for your model (e.g., bctgl357.0050 is less than bctgl357.0064)
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Confirm local access conditionVerify that the system permits local user authentication (standard multi-user Linux/Windows installations). This is a precondition since the vulnerability requires an authenticated local user to trigger the out-of-bounds writeAffected if The system is configured such that no local authenticated users can log in (extremely rare for general-purpose systems)
You are affected by CVE-2021-33086 if you own one of the eight listed Intel NUC models AND your current firmware version is below the specified minimum version for that model, and the system allows local user authentication.
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 · scopedApply the latest Intel firmware update for affected NUC devices. Verify your specific NUC model is impacted, then download and install the corresponding firmware update from Intel's support website, following their firmware update instructions carefully.
Upgrade to firmware bctgl357.0064 (M15 models), ebtgl357.0056 (Compute Element models), or patgl357.0040 (Performance Kit models) depending on specific hardware model
- Identify the exact model number of the Intel NUC or Laptop Kit from the affected product list
- Determine the current firmware version installed on the device
- Download the corresponding firmware update from Intel's support website: https://www.intel.com/content/www/us/en/support.html
- For Nuc M15 Laptop Kit Lapbc510/Lapbc710: Update to firmware version bctgl357.0064 or later
- For Nuc 11 Compute Element models (Cm11ebc4w, Cm11ebi38w, Cm11ebi58w, Cm11ebi716w): Update to firmware version ebtgl357.0056 or later
- For Nuc 11 Performance Kit (Nuc11pahi3, Nuc11pahi5): Update to firmware version patgl357.0040 or later
- Follow Intel's standard firmware update procedure, typically using the Intel® Flash BIOS Update utility or firmware capsule
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33086 — 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-2021-33086 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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