CVE-2021-20699
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 · uneditedSharp NEC Displays ((UN462A R1.300 and prior to it, UN462VA R1.300 and prior to it, UN492S R1.300 and prior to it, UN492VS R1.300 and prior to it, UN552A R1.300 and prior to it, UN552S R1.300 and prior to it, UN552VS R1.300 and prior to it, UN552 R1.300 and prior to it, UN552V R1.300 and prior to it, UX552S R1.300 and prior to it, UX552 R1.300 and prior to it, V864Q R2.000 and prior to it, C861Q R2.000 and prior to it, P754Q R2.000 and prior to it, V754Q R2.000 and prior to it, C751Q R2.000 and prior to it, V984Q R2.000 and prior to it, C981Q R2.000 and prior to it, P654Q R2.000 and prior to it, V654Q R2.000 and prior to it, C651Q R2.000 and prior to it, V554Q R2.000 and prior to it, P404 R3.200 and prior to it, P484 R3.200 and prior to it, P554 R3.200 and prior to it, V404 R3.200 and prior to it, V484 R3.200 and prior to it, V554 R3.200 and prior to it, V404-T R3.200 and prior to it, V484-T R3.200 and prior to it, V554-T R3.200 and prior to it, C501 R2.000 and prior to it, C551 R2.000 and prior to it, C431 R2.000 and prior to it) allows an attacker a buffer overflow and to execute remote code by sending long parameters that contains specific characters in http request.
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 confidenceBuffer overflow vulnerability in Sharp NEC commercial display web interfaces allows remote attackers to execute arbitrary code via specially crafted HTTP requests containing long parameters with specific characters. The vulnerability is exploitable without authentication and affects multiple display models across UN, V, C, P, and UX series.
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<= r1.300<= r1.300<= r1.300<= r1.300<= r1.300<= r1.300<= r1.300<= r1.300CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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 display modelLocate the model number on the physical display unit (typically on a label on the back or side) or access the display's on-screen menu system to find the model information. Confirm the model falls within the UN, V, C, P, or UX series product line.Affected if The model is one of the specifically listed affected models (UN462a, UN462va, UN492s, UN492vs, UN552a, UN552s, UN552vs, UN552) or belongs to the broader UN/V/C/P/UX series families noted in the CVE.
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Check the installed firmware versionAccess the display's web management interface (typically via the display's IP address in a browser) and navigate to the firmware or system information page. Look for a version field that displays the current firmware revision (such as 'r1.300' or similar).Affected if The displayed firmware version is r1.300 or any version number lower than r1.300.
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Confirm the web management interface is enabledAttempt to access the display by entering its IP address in a web browser. Verify that a login page or management interface loads successfully.Affected if The web interface is accessible and responds to HTTP requests, indicating it is enabled and network-reachable.
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Verify network exposure of the management interfaceReview your network configuration or firewall rules to determine whether the display's web management port (typically port 80 or 443) is exposed to untrusted networks or the internet.Affected if The web management interface is reachable from networks outside your trusted internal environment, making it a potential target for remote exploitation.
You are affected if your display model is in the UN, V, C, P, or UX series, runs firmware version r1.300 or lower, and has its web management interface enabled and network-accessible.
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 vendor-supplied firmware updates (R1.301 for UN series, R2.001 for V/C/P series, R3.201 for P/V-T series) to address the buffer overflow. If updates are unavailable, restrict network access to display management interfaces.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20699 — 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-2021-20699 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
- No weaponised exploit code, or anything meant to cause harm
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