Ac20 FirmwareOperating system · Tenda

CVE-2025-10815

HIGH · 8.8 CVSS v3.1 Published 2025-09-22
Fix available
A fix is available. Upgrade to after 16.03.08.12 or later.
See remediation →
94/100
Remediation priority · Urgent
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
A vulnerability was identified in Tenda AC20 up to 16.03.08.12. Affected by this issue is the function strcpy of the file /goform/SetPptpServerCfg of the component HTTP POST Request Handler. Such manipulation of the argument startIp leads to buffer overflow. The attack can be launched remotely. The exploit is publicly available and might 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

Buffer overflow vulnerability in Tenda AC20 routers (firmware up to 16.03.08.12) in the PPTP server configuration handler (/goform/SetPptpServerCfg). The strcpy function copies the user-controlled 'startIp' parameter from HTTP POST requests without bounds checking, allowing remote attackers to overflow a buffer and potentially achieve code execution.

MitigationApply vendor firmware patch when available; until then, disable PPTP server functionality on affected devices and restrict network access to the router's web 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
Ac20 FirmwareOperating system
Affected:<= 16.03.08.12

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

CVSS:3.1/AV:N/AC:L/PR:L/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
    Check the device label or login to the router web interface and look for the model number (typically displayed on the status or system info page)
    Affected if Device is not a Tenda AC20 router (this CVE only affects AC20 models)
  2. Determine firmware version
    In the router web interface, navigate to System Settings or Administration > Firmware Upgrade (or similar) to view the current firmware version; alternatively, check the firmware file name if you have access to the firmware binary
    Affected if Firmware version is 16.03.08.12 or earlier (versions after 16.03.08.12 may contain the fix)
  3. Verify PPTP server functionality is enabled
    In the router web interface, look for PPTP server settings under Advanced Settings, VPN, or similar section; check if the PPTP server is turned ON or enabled
    Affected if PPTP server is enabled - the vulnerability requires the PPTP server feature to be active to be exploitable

You are affected if you have a Tenda AC20 router running firmware version 16.03.08.12 or earlier with the PPTP server feature enabled.

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 a release after 16.03.08.12
Interim mitigation

Apply vendor firmware patch when available; until then, disable PPTP server functionality on affected devices and restrict network access to the router's web interface.

Fix this in Ac20 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2025-10815 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