T10 FirmwareOperating system · Totolink

CVE-2025-14964

CRITICAL · 9.8 CVSS v3.1 Published 2025-12-19
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 vulnerability has been found in TOTOLINK T10 4.1.8cu.5083_B20200521. This affects the function sprintf of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument loginAuthUrl leads to stack-based buffer overflow. The attack may be performed from remote.

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

A stack-based buffer overflow vulnerability exists in the TOTOLINK T10 router firmware (v4.1.8cu.5083_B20200521). The sprintf function in the CGI binary /cgi-bin/cstecgi.cgi does not properly validate the length of the loginAuthUrl parameter before copying it to a fixed-size stack buffer, allowing remote attackers to overwrite return addresses and potentially execute arbitrary code.

MitigationUpdate to a patched firmware version if available; if no patch exists, disable remote administration interfaces, block external access to the web interface via firewall rules, and consider replacing the device.

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
T10 FirmwareOperating system
Affected:= 4.1.8cu.5803_b20200521

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 device model
    Check the router label or access the web interface to confirm the device is a TOTOLINK T10 model
    Affected if Device is not a TOTOLINK T10 router
  2. Check firmware version
    Access the router admin panel or use telnet/SSH if available, then navigate to System Status or Firmware Upgrade page to view the installed firmware version. Alternatively, check the banner/version string via telnet/SSH access
    Affected if Firmware version is 4.1.8cu.5803_b20200521 (exact match to affected version)
  3. Verify vulnerable CGI binary exists
    If web interface is accessible, attempt to access http://router_ip/cgi-bin/cstecgi.cgi - the binary should exist on affected firmware
    Affected if The /cgi-bin/cstecgi.cgi endpoint responds (indicates vulnerable binary is present)
  4. Check if remote web management is enabled
    In the router web interface, go to Advanced Settings > Remote Management (or similar) and check if Remote Web Management is enabled. Also check the WAN-facing HTTP service listening on port 80/443
    Affected if Remote web management is enabled, exposing the CGI interface to the internet

User is affected if they have a TOTOLINK T10 router running firmware version 4.1.8cu.5803_b20200521 with the vulnerable cstecgi.cgi binary, especially if remote web management is exposed to untrusted networks

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

Update to a patched firmware version if available; if no patch exists, disable remote administration interfaces, block external access to the web interface via firewall rules, and consider replacing the device.

Fix this in T10 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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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-2025-14964 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
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