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R6400 FirmwareOperating system · Netgear

CVE-2021-38523

HIGH · 7.2 CVSS v3.1 Published 2021-08-11
Fix available
A fix is available. Upgrade to 1.0.1.70 or later.
See remediation →
78/100
Remediation priority · High
Remotely reachable 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
NETGEAR R6400 devices before 1.0.1.70 are affected by a stack-based buffer overflow by an authenticated user.

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

NETGEAR R6400 devices before firmware version 1.0.1.70 contain a stack-based buffer overflow vulnerability in the web management interface. An authenticated attacker with access to the router's admin panel can exploit this memory corruption vulnerability to potentially execute arbitrary code or cause denial of service.

MitigationUpdate NETGEAR R6400 firmware to version 1.0.1.70 or later. If immediate patching is not feasible, limit administrative access to trusted users only and disable remote management if not required.

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
R6400 FirmwareOperating system
Affected:< 1.0.1.70

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
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/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. Confirm the device model is NETGEAR R6400
    Log into the router's web management interface and locate the device information or status page to verify the exact model number displayed.
    Affected if The device model shown is NETGEAR R6400.
  2. Determine the installed firmware version
    In the router's web admin interface, navigate to the Firmware Update, Router Status, or Administration section and locate the firmware version field. Record the exact version number displayed.
    Affected if The displayed firmware version is lower than 1.0.1.70 (for example, 1.0.1.64, 1.0.0.94, etc.).
  3. Verify the web management interface is accessible
    Attempt to access the router's admin panel by entering the router's IP address in a web browser. Confirm the login page loads and accepts authentication.
    Affected if The web management interface is enabled and reachable on the local network or remotely.
  4. Check if remote management is enabled
    In the router's web interface, look for settings under Advanced, Administration, or Remote Management. Determine whether the option to allow management from outside the local network is turned on.
    Affected if Remote web management is enabled, expanding the attack surface for an authenticated attacker.

The device is affected if it is a NETGEAR R6400 running firmware version lower than 1.0.1.70 and the web management interface is accessible.

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.

dbcve · scoped
Upgrade available Upgrade to 1.0.1.70 or later
Fixed in 1.0.1.70
Interim mitigation

Update NETGEAR R6400 firmware to version 1.0.1.70 or later. If immediate patching is not feasible, limit administrative access to trusted users only and disable remote management if not required.

Recommended fix High confidence

R6400 Firmware version 1.0.1.70 or later

  1. Download firmware version 1.0.1.70 (or later) from the official NETGEAR support page for the R6400 at kb.netgear.com
  2. Access the router's web management interface by navigating to routerlogin.net or 192.168.1.1
  3. Log in with administrator credentials
  4. Navigate to the Advanced tab > Administration > Firmware Update section
  5. Click 'Check for Updates' or select the option to manually upload firmware
  6. Upload the downloaded firmware file (e.g., R6400-V1.0.1.70.bin)
  7. Wait for the firmware upload to complete - do not power off the router
  8. The router will automatically reboot after the update finishes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in R6400 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
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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-2021-38523 in production — separate from our analysis above.

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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