CVE-2018-21227
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 command injection by an authenticated user. This affects D7800 before 1.0.1.34, R6400v2 before 1.0.2.34, R6700 before 1.0.1.30, R6900 before 1.0.1.30, R6900P before 1.0.0.62, R7000 before 1.0.9.12, R7000P before 1.0.0.62, R7500v2 before 1.0.3.26, R7800 before 1.0.2.42, R9000 before 1.0.3.10, WNDR4300v2 before 1.0.0.50, and WNDR4500v3 before 1.0.0.50.
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 confidenceAuthenticated command injection vulnerability in multiple NETGEAR router models (D7800, R6400v2, R6700, R6900, R6900P, R7000, R7000P, R7500v2, R7800, R9000, WNDR4300v2, WNDR4500v3). An authenticated attacker can execute arbitrary OS commands via insecure input handling in the web management interface.
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< 1.0.1.34< 1.0.2.34< 1.0.1.30< 1.0.1.30< 1.0.0.62< 1.0.9.12< 1.0.0.62< 1.0.3.26CVSS 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 router modelCheck the product label on the router bottom/side, or log into the web management interface and locate the model number on the main status pageAffected if Router is one of: D7800, R6400v2, R6700, R6900, R6900P, R7000, R7000P, R7500v2, R7800, R9000, WNDR4300v2, or WNDR4500v3
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Locate the installed firmware versionIn the web interface, go to Administration > Firmware Update or Router Status to view the current firmware version. The version is typically displayed on the main dashboard or in the router status sectionAffected if A firmware version is displayed that can be compared to the affected ranges
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Compare firmware to affected version rangesMatch your router model and firmware version against the vulnerable ranges: D7800 < 1.0.1.34, R6400v2 < 1.0.2.34, R6700 < 1.0.1.30, R6900 < 1.0.1.30, R6900P < 1.0.0.62, R7000 < 1.0.9.12, R7000P < 1.0.0.62, R7500v2 < 1.0.3.26Affected if The installed firmware version is below the threshold listed for your specific model
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Verify if web management interface is accessibleCheck the router's Remote Management settings (typically under Administration > Remote Management) to determine if the web interface can be accessed from LAN or WAN. Also confirm you have valid admin credentialsAffected if You can access the web management interface with valid credentials and the router firmware is in the affected version range
If the router model matches one of the affected models AND the installed firmware version is below the specified threshold, the device is vulnerable to authenticated command injection via the web management 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 data1.0.0.621.0.1.301.0.1.34
Update affected routers to the latest firmware versions specified in the advisory (D7800: 1.0.1.34, R6400v2: 1.0.2.34, R6700/R6900: 1.0.1.30, R7000: 1.0.9.12, etc.). If patching is not immediately possible, limit administrative access to trusted users and monitor for suspicious activity.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-21227 — 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-2018-21227 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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