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R8000 FirmwareOperating system · Netgear

CVE-2021-34236

CRITICAL · 9.8 CVSS v3.1 Published 2022-09-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
Buffer Overflow in Netgear R8000 Router with firmware v1.0.4.56 allows remote attackers to execute arbitrary code or cause a denial-of-service by sending a crafted POST to '/bd_genie_create_account.cgi' with a sufficiently long parameter 'register_country'.

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

Buffer overflow vulnerability in Netgear R8000 routers (firmware v1.0.4.56) in the /bd_genie_create_account.cgi script. The 'register_country' POST parameter lacks proper length validation, allowing attackers to overflow the buffer and achieve remote code execution or cause denial of service.

MitigationApply vendor firmware update when available; if no update exists, disable the Genie feature/service or implement network segmentation to restrict access to the router's 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
R8000 FirmwareOperating system
Affected:= 1.0.4.56

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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's admin interface (typically at 192.168.1.1) and navigate to the Administration or Settings section to confirm the device model is Netgear R8000, or check the device label on the router hardware itself
    Affected if The device is not a Netgear R8000 router (not affected)
  2. Check firmware version
    In the router admin interface, go to Administration > Firmware Update or Advanced > Administration > Router Update to view the current firmware version. Alternatively, check the file named 'R8000-V1.0.4.56.bin' if you have firmware files, or access the router's telnet/ssh interface and run 'nvram get fw_version' or similar command to retrieve firmware version
    Affected if Firmware version is exactly 1.0.4.56 (exact match required per CVEs)
  3. Verify Genie service accessibility
    Attempt to access the CGI script endpoint via HTTP POST request to http://<router-ip>/bd_genie_create_account.cgi. This can be tested using a tool like curl: curl -X POST http://192.168.1.1/bd_genie_create_account.cgi -d 'test=1'
    Affected if The /bd_genie_create_account.cgi script is accessible and responds to requests (vulnerable endpoint exists)
  4. Confirm register_country parameter handling
    Send a crafted POST request with an overly long string in the 'register_country' parameter (e.g., register_country=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...) to /bd_genie_create_account.cgi and observe if the router crashes, reboots, or returns an error indicating buffer overflow
    Affected if The router exhibits abnormal behavior (crash, reboot, or no response) when sending long strings to register_country parameter

You are affected if you are running Netgear R8000 firmware exactly version 1.0.4.56 and the Genie feature with its /bd_genie_create_account.cgi endpoint is accessible on your network.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware update when available; if no update exists, disable the Genie feature/service or implement network segmentation to restrict access to the router's management interface.

Recommended fix Moderate confidence

R8000 Firmware 1.0.4.120 or later

  1. Check Netgear's official support website for the R8000 router firmware updates
  2. Navigate to the Netgear R8000 support page and look for firmware version 1.0.4.120 or later
  3. Download the latest firmware version available from Netgear
  4. Access the router's web interface and upload the new firmware
  5. Alternatively, use the Netgear Nighthawk app to check for and apply firmware updates
  6. After updating, verify the firmware version in the router settings

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

Fix this in R8000 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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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-2021-34236 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
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