R7800 FirmwareOperating system · Netgear

CVE-2018-21183

MEDIUM · 6.8 CVSS v3.1 Published 2020-04-28
Fix available
A fix is available. Upgrade to 1.0.2.40 / 1.0.2.52 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 R7800 before 1.0.2.40, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.92, and WNDR4300 before 1.0.2.94.

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

This is a stack-based buffer overflow vulnerability in NETGEAR router firmware (R7800, R9000, WNDR3700v4, WNDR4300) that can be exploited by an authenticated user, potentially leading to arbitrary code execution or device compromise.

MitigationUpdate NETGEAR router firmware to version R7800 1.0.2.40+, R9000 1.0.2.52+, WNDR3700v4 1.0.2.92+, or WNDR4300 1.0.2.94+ respectively. Restrict administrative access to trusted users only.

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
R7800 FirmwareOperating system
Affected:< 1.0.2.40
R9000 FirmwareOperating system
Affected:< 1.0.2.52
Wndr3700 FirmwareOperating system
Affected:< 1.0.2.92
Wndr4300 FirmwareOperating system
Affected:< 1.0.2.94

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
    Locate the model number on the device label or access the router web interface (typically at 192.168.1.1) and check the device info or status page
    Affected if The model is R7800, R9000, WNDR3700v4, or WNDR4300
  2. Find firmware version
    In the router web interface, navigate to Administration > Firmware Update or Advanced > Administration > Router Status to view the current firmware version
    Affected if The displayed firmware version is below 1.0.2.40 for R7800, below 1.0.2.52 for R9000, below 1.0.2.92 for WNDR3700v4, or below 1.0.2.94 for WNDR4300
  3. Verify administrative access method
    Check if remote management (Web GUI access from WAN) is enabled in the router settings under Advanced > Administration > Remote Management
    Affected if Remote management is enabled and accessible from untrusted networks, increasing exploitability
  4. Confirm authentication state
    Determine whether user credentials for the router admin interface are in use and whether they could be compromised
    Affected if The router admin credentials are known to untrusted users or have not been changed from defaults

The router is affected if it is an R7800, R9000, WNDR3700v4, or WNDR4300 model running firmware version below the respective thresholds (1.0.2.40, 1.0.2.52, 1.0.2.92, 1.0.2.94) and the administrative interface is accessible to an authenticated attacker.

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 1.0.2.40 / 1.0.2.52 / 1.0.2.92 or later
Fixed in 1.0.2.401.0.2.521.0.2.92
Interim mitigation

Update NETGEAR router firmware to version R7800 1.0.2.40+, R9000 1.0.2.52+, WNDR3700v4 1.0.2.92+, or WNDR4300 1.0.2.94+ respectively. Restrict administrative access to trusted users only.

Fix this in R7800 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2018-21183 — 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-2018-21183 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