CVE-2021-20645
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 · uneditedCross-site scripting vulnerability in ELECOM WRC-300FEBK-A allows remote authenticated attackers to inject arbitrary script via unspecified vectors.
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 confidenceAuthenticated cross-site scripting vulnerability in the ELECOM WRC-300FEBK-A wireless router web interface allows remote attackers to inject arbitrary JavaScript or HTML through unsanitized input fields in unspecified areas of the router's administrative panel.
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 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
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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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Confirm router model is WRC-300FEBK-ALocate the physical device or check the administrative interface for the model identifier WRC-300FEBK-A. This is typically found on a label on the device underside or in the web interface header/status page.Affected if The device model is Elecom Wrc 300febk A
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Verify administrative web interface is presentAttempt to access the router's web interface by entering the router's IP address in a browser. Common default addresses are 192.168.0.1 or 192.168.1.1. Look for an ELECOM login page.Affected if The router web interface is accessible at its IP address
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Confirm remote or unauthenticated access vectorDetermine if the administrative interface is exposed to the network beyond the local LAN, or if an attacker with access to the interface could submit input. For this XSS, the attacker needs authenticated access to submit malicious script tags in input fields.Affected if The administrative panel accepts user input and an attacker could authenticate to reach those input fields
If the device is an Elecom WRC-300FEBK-A with an accessible web administrative panel that accepts user input, the environment is affected since all firmware versions contain this vulnerability.
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 update when available; until then, restrict administrative access to trusted users only and avoid accessing the router interface from untrusted networks.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20645 — 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-2021-20645 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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