D6100 FirmwareOperating system · Netgear

CVE-2018-21191

MEDIUM · 6.8 CVSS v3.1 Published 2020-04-28
Fix available
A fix is available. Upgrade to 1.0.0.50 / 1.0.0.57 or later.
See remediation →
70/100
Remediation priority · Elevated
Zero-click

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 · unedited
Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D6100 before 1.0.0.57, R6100 before 1.0.1.20, R7800 before 1.0.2.40, WNDR3700v4 before 1.0.2.92, WNDR4300 before 1.0.2.94, 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 · high confidence

Stack-based buffer overflow vulnerability in multiple NETGEAR router models (D6100, R6100, R7800, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, WNR2000v5) that can be exploited by an authenticated user, potentially allowing arbitrary code execution or device compromise.

MitigationUpdate router firmware to the specified versions: D6100 to 1.0.0.57, R6100 to 1.0.1.20, R7800 to 1.0.2.40, WNDR3700v4 to 1.0.2.92, WNDR4300 to 1.0.2.94, WNDR4300v2 to 1.0.0.50, WNDR4500v3 to 1.0.0.50, and WNR2000v5 to 1.0.0.62.

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
D6100 FirmwareOperating system
Affected:< 1.0.0.57
R6100 FirmwareOperating system
Affected:< 1.0.1.20
R7800 FirmwareOperating system
Affected:< 1.0.2.40
Wndr3700 FirmwareOperating system
Affected:< 1.0.2.92
Wndr4300 FirmwareOperating system
Affected:< 1.0.2.92< 1.0.0.50
Wndr4500 FirmwareOperating system
Affected:< 1.0.0.50
Wnr2000 FirmwareOperating system
Affected:< 1.0.0.62

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify router model
    Access the router admin interface and look for the model number in the status or settings page, or check the device label on the router itself
    Affected if Model is D6100, R6100, R7800, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, or WNR2000v5
  2. Check installed firmware version
    In the router web interface, navigate to Administration or Settings and locate the Firmware Version field; alternatively, check the status page
    Affected if Firmware version cannot be determined or is below the fixed version for your model
  3. Compare version against affected ranges
    Reference the firmware version found and compare it to the affected thresholds: D6100 < 1.0.0.57, R6100 < 1.0.1.20, R7800 < 1.0.2.40, WNDR3700 < 1.0.2.92, WNDR4300 < 1.0.2.92 (or < 1.0.0.50 for v2), WNDR4500 < 1.0.0.50, WNR2000 < 1.0.0.62
    Affected if Installed firmware version is lower than the fixed version for your specific model and variant

The environment is affected if the router model is one of the eight affected models and the installed firmware version falls below the version threshold for that model.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to 1.0.0.50 / 1.0.0.57 / 1.0.0.62 or later
Fixed in 1.0.0.501.0.0.571.0.0.62
Interim mitigation

Update router firmware to the specified versions: D6100 to 1.0.0.57, R6100 to 1.0.1.20, R7800 to 1.0.2.40, WNDR3700v4 to 1.0.2.92, WNDR4300 to 1.0.2.94, WNDR4300v2 to 1.0.0.50, WNDR4500v3 to 1.0.0.50, and WNR2000v5 to 1.0.0.62.

Fix this in D6100 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-21191 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-21191 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data