CVE-2021-20738
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 · uneditedWRC-1167FS-W, WRC-1167FS-B, and WRC-1167FSA all versions allow an unauthenticated network-adjacent attacker to obtain sensitive information 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 confidenceBuffalo WRC-1167 series wireless routers contain an information disclosure vulnerability allowing unauthenticated, network-adjacent attackers to obtain sensitive information. The attack requires the attacker to be on the same network segment but does not require authentication. The specific attack vector and exact nature of the sensitive information is not specified in the advisory.
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 versionsall versionsall 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/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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Identify the router modelCheck the device label on the router or log into the web administrative interface to view the model numberAffected if The model is Elecom Wrc 1167fs W, Elecom Wrc 1167fs B, Elecom Wrc 1167fsa, or Buffalo WRC-1167 series
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Verify all firmware versions are affectedCheck the installed firmware version in the router's administrative interface under the firmware or status sectionAffected if The device is one of the affected models regardless of firmware version - all versions are vulnerable
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Determine network exposureCheck if the router's web management interface (typically HTTP/HTTPS on ports 80 or 443) is accessible from network segments that contain untrusted devices or are exposed to guest networksAffected if The management interface is reachable from any network segment beyond your trusted internal network
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Assess attack surfaceConfirm whether the router is deployed in an environment where network-adjacent attackers could reach it (shared WiFi, insufficient network segmentation, or flat network topologies)Affected if The router is on a network segment accessible to untrusted or guest devices
If you have deployed any Elecom Wrc 1167fs or Buffalo WRC-1167 series router and its management interface is accessible from network segments beyond your trusted internal network, 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 dataIf firmware updates are available from Buffalo, apply them immediately. Otherwise, restrict network access to these devices using VLANs or firewall rules to limit exposure to only trusted network segments, and monitor for signs of unauthorized access.
- Consultation4.0 h
- Implementation8.0 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 $4,880.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20738 — 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-2021-20738 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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- 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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