CVE-2018-21220
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 · uneditedCertain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D3600 before 1.0.0.67, D6000 before 1.0.0.67, D6100 before 1.0.0.56, D7800 before 1.0.1.30, R6100 before 1.0.1.20, R7500 before 1.0.0.118, R7500v2 before 1.0.3.24, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.50, WNDR4500v3 before 1.0.0.50, and WNR2000v5 before 1.0.0.62.
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 confidenceA buffer overflow vulnerability in multiple NETGEAR router models (D3600, D6000, D6100, D7800, R6100, R7500, R7500v2, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, WNR2000v5) that can be exploited by an unauthenticated remote attacker, allowing potential code execution or device compromise.
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< 1.0.0.62< 1.0.2.52< 1.0.2.96< 1.0.2.98< 1.0.0.50< 1.0.0.118< 1.0.3.24< 1.0.0.50< 1.0.1.20< 1.0.1.30CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:A/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 your NETGEAR router modelLocate the model number on the device label on the bottom or back of the router, or log into the router web interface and check the status or device info pageAffected if The model is one of: D3600, D6000, D6100, D7800, R6100, R7500, R7500v2, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, or WNR2000v5
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Determine the installed firmware versionLog into the router web interface (typically 192.168.1.1), navigate to Administration > Firmware Update or Router Status, and record the firmware version displayedAffected if The firmware version cannot be determined or the router is accessible via web interface
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Compare firmware version against affected rangesMatch your model and firmware version against these thresholds: WNR2000 < 1.0.0.62; R9000 < 1.0.2.52; WNDR3700 < 1.0.2.96; WNDR4300 < 1.0.2.98 or < 1.0.0.50; R7500 < 1.0.0.118 or < 1.0.3.24; WNDR4500 < 1.0.0.50; R6100 < 1.0.1.20; D7800 < 1.0.1.30Affected if Your firmware version is lower than the listed threshold for your specific model
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Verify remote management is accessibleCheck if the router's web interface is reachable from the WAN/internet side, or test if ports 80/443 are exposed externally using a port scannerAffected if The router administration interface is exposed to the internet and the firmware is in the affected version range
You are affected if you own one of the listed NETGEAR models and your installed firmware version falls below the threshold for that model, especially if the router admin interface is internet-facing.
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 data1.0.0.501.0.0.621.0.0.118
Apply vendor-supplied firmware updates to patch the buffer overflow vulnerability on all affected NETGEAR router models; if patches are unavailable, consider network segmentation or device replacement.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-21220 — 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-2018-21220 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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