CVE-2018-21111
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 stack-based buffer overflow by an authenticated user. This affects D3600 before 1.0.0.75, D6000 before 1.0.0.75, D6100 before 1.0.0.60, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, WNDR3700v4 before 1.0.2.102, WNDR4300 before 1.0.2.104, WNDR4300v2 before 1.0.0.58, WNDR4500v3 before 1.0.0.58, and WNR2000v5 before 1.0.0.66.
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 confidenceMultiple NETGEAR router models contain a stack-based buffer overflow vulnerability that can be exploited by an authenticated attacker. The vulnerability allows specially crafted input to overflow a buffer on the stack, potentially enabling arbitrary code execution or device compromise. Affected devices span multiple model lines including D-series, R-series, and WNDR/WNR series routers with specific unpatched firmware versions.
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< 1.0.0.75< 1.0.0.75< 1.0.0.60< 1.0.2.52< 1.0.4.2< 1.0.4.2< 1.0.2.102< 1.0.2.104< 1.0.0.58CVSS 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 router modelCheck the device label on the router or log into the admin interface to confirm the exact model number (D3600, D6000, D6100, R7800, R8900, R9000, Wndr3700, or Wndr4300).Affected if Router model is one of the eight affected models listed in the CVE.
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Check installed firmware versionLog into the router web interface and navigate to the Administration or Firmware Update section to view the current firmware version. Alternatively, check NETGEAR's support site for your model using the serial number.Affected if Firmware version cannot be determined or is below the patched version for your model.
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Compare version to patched releasesCompare your installed firmware version against the fixed versions: D3600/D6000 should be >= 1.0.0.75, D6100 >= 1.0.0.60, R7800 >= 1.0.2.52, R8900/R9000 >= 1.0.4.2, Wndr3700 >= 1.0.2.102, Wndr4300 >= 1.0.2.104 (or >= 1.0.0.58 for certain revisions).Affected if Your firmware version is lower than the fixed version for your specific model.
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Verify admin interface accessibilityDetermine if the router's web-based administration interface is accessible from the WAN (internet) side. Check the Remote Management or Web Service settings in the router configuration.Affected if Remote management is enabled and the admin interface is reachable from untrusted networks.
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Assess authentication exposureReview whether the router admin credentials are known to untrusted users or if default credentials remain in use. The vulnerability requires an authenticated attacker.Affected if Attacker can obtain valid credentials to log into the router admin interface.
You are affected if your router model matches one of the eight listed models, your firmware version is below the fixed version for that model, and an attacker can authenticate to the admin interface.
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 data1.0.0.581.0.0.601.0.0.75
Apply vendor-provided firmware updates to the specific versions listed (e.g., D3600 to 1.0.0.75, R7800 to 1.0.2.52, WNDR4300 to 1.0.2.104). If updates cannot be applied immediately, restrict administrative interface access to trusted users only and disable unauthenticated remote management.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-21111 — 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-2018-21111 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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