Ac21 FirmwareOperating system · Tenda

CVE-2025-13445

CRITICAL · 9.8 CVSS v3.1 Published 2025-11-20
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
Public exploit 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
A flaw has been found in Tenda AC21 16.03.08.16. This affects an unknown part of the file /goform/SetIpMacBind. Executing a manipulation of the argument list can lead to stack-based buffer overflow. The attack can be executed remotely. The exploit has been published and may be used.

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 in Tenda AC21 router firmware 16.03.08.16 within the /goform/SetIpMacBind form handler. The vulnerability allows remote attackers to overflow a stack-allocated buffer via manipulated argument values, potentially enabling arbitrary code execution.

MitigationApply vendor firmware patch when available; until then, disable or restrict access to the affected web interface (port 80/443) via firewall rules or network segmentation to prevent remote exploitation.

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
Ac21 FirmwareOperating system
Affected:= 16.03.08.16

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. Confirm device is Tenda AC21
    Access the router web interface or physically inspect the device label to verify the model number is AC21
    Affected if Device is not a Tenda AC21 router
  2. Identify installed firmware version
    Log into the router web interface and navigate to the System Settings, Administration, or Firmware Upgrade page to view the current firmware version. Alternatively, check via telnet/ssh if remote access is enabled
    Affected if Firmware version is exactly 16.03.08.16
  3. Verify SetIpMacBind endpoint is present
    Send an HTTP request to http://[router-ip]/goform/SetIpMacBind and observe if the endpoint exists and responds
    Affected if The endpoint exists and is accessible
  4. Assess network accessibility of management interface
    Determine whether the router web interface (HTTP port 80 or HTTPS port 443) is exposed to the internet or accessible from untrusted network segments
    Affected if Management interface is reachable from untrusted networks

User is affected if running Tenda AC21 firmware version 16.03.08.16 with the SetIpMacBind endpoint accessible from an attacker's network location

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 vendor firmware patch when available; until then, disable or restrict access to the affected web interface (port 80/443) via firewall rules or network segmentation to prevent remote exploitation.

Fix this in Ac21 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-13445 — 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-2025-13445 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