Ac6 FirmwareOperating system · Tenda

CVE-2023-40830

CRITICAL · 9.8 CVSS v3.1 Published 2023-10-03
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
Tenda AC6 v15.03.05.19 is vulnerable to Buffer Overflow as the Index parameter does not verify the length.

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 · moderate confidence

Tenda AC6 router firmware v15.03.05.19 contains a buffer overflow vulnerability in the handling of the Index parameter due to missing length validation. An unauthenticated attacker could potentially send specially crafted requests with an overly long Index value to trigger the overflow, potentially leading to remote code execution.

MitigationApply any vendor firmware update when available. If no update exists, implement input length validation on the Index parameter in the affected web interface code and consider network segmentation to limit exposure.

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
Ac6 FirmwareOperating system
Affected:= 15.03.05.19

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 the device model
    Access the router admin interface or check the device label/marketing to confirm the model is Tenda AC6
    Affected if The device is not a Tenda AC6 router, then it is not affected by this specific CVE
  2. Check the firmware version
    Log into the router web interface and navigate to System Settings > Firmware Upgrade or check under Administration > Device Info to find the firmware version. Alternatively, use telnet/SSH if enabled and run 'cat /proc/version' or check /etc/firmware_version
    Affected if The firmware version is not 15.03.05.19, then it is not affected by this specific CVE (only version 15.03.05.19 is listed as affected)
  3. Verify the web interface is accessible
    Attempt to access the router login page via HTTP/HTTPS at the router IP address (commonly 192.168.0.1 or 192.168.1.1). Confirm the page loads and shows the Tenda login
    Affected if The web interface is not accessible from your testing location, the attack surface may be reduced but the vulnerability still exists in the firmware if version is 15.03.05.19
  4. Confirm the Index parameter handler exists
    Locate the CGI binary or web handler that processes the Index parameter in the firmware. This is typically found in /bin/httpd or similar web server binaries. Use 'strings' or binwalk on the firmware if accessible, or check for the specific web endpoint that accepts the Index parameter
    Affected if The specific handler that processes the Index parameter is present and the firmware version is 15.03.05.19, then the device is affected by this buffer overflow vulnerability

If the device is a Tenda AC6 router running firmware version 15.03.05.19 with the web interface accessible, it is affected by this CVE.

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

Apply any vendor firmware update when available. If no update exists, implement input length validation on the Index parameter in the affected web interface code and consider network segmentation to limit exposure.

Fix this in Ac6 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2023-40830 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
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  • Version or environment caveats, and links to real fixes
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