CVE-2021-20648
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 · uneditedELECOM WRC-300FEBK-S allows an attacker with administrator rights to execute arbitrary OS commands 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 command injection vulnerability in ELECOM WRC-300FEBK-S wireless router. An attacker with administrator-level credentials can execute arbitrary OS commands on the device, likely through insufficient input validation in a web interface or API parameter that gets passed to system shell calls.
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
- Adjacent
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/AC:L/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 device modelAccess the router admin panel (typically at 192.168.0.1) or physically inspect the device label to confirm the exact model is ELECOM WRC-300FEBK-SAffected if The device is an ELECOM WRC-300FEBK-S router (all firmware versions are affected)
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Confirm firmware versionIn the router web interface, navigate to the firmware or system information page and note the installed firmware versionAffected if Any firmware version is installed (all versions are vulnerable)
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Check if remote web management is enabledIn the router admin panel, look for settings such as 'Remote Management', 'WAN Access', or 'Web Access from WAN' and verify whether remote access is permittedAffected if Remote web management is enabled and the interface is accessible from outside the local network
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Verify administrative credential securityConfirm that default administrator credentials have been changed and are not using factory-default usernames/passwordsAffected if Default credentials are in use or credentials may have been compromised
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Assess network exposure of admin interfaceFrom an external network (or using a mobile hotspot), attempt to reach the router's IP address on ports 80/443 to determine if the admin interface is reachable from untrusted networksAffected if The web interface is reachable from untrusted/external networks
If you are using an ELECOM WRC-300FEBK-S router with its web interface accessible to untrusted networks and administrative credentials are known to an attacker, you are affected by 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 dataRestrict administrative access to trusted IP addresses only, disable remote web management if not required, and apply any vendor firmware updates. If no patch is available, consider replacing the device or implementing network segmentation to isolate the router.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20648 — 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-2021-20648 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
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