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X18 FirmwareOperating system · Totolink

CVE-2025-1340

HIGH · 8.8 CVSS v3.1 Published 2025-02-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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 classified as critical has been found in TOTOLINK X18 9.1.0cu.2024_B20220329. Affected is the function setPasswordCfg of the file /cgi-bin/cstecgi.cgi. The manipulation as part of String leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

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 the setPasswordCfg function of TOTOLINK X18 router's cgi-bin/cstecgi.cgi binary. The function fails to properly validate string length before copying user-supplied input to a fixed-size stack buffer, allowing remote attackers to overwrite return addresses and potentially execute arbitrary code.

MitigationSince the vendor has not responded to the disclosure, implement compensating controls: restrict remote access to the router's web interface via firewall rules, disable WAN-facing management if possible, and monitor for exploitation attempts. Replace the device with a supported model if the vendor does not release a firmware patch.

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
X18 FirmwareOperating system
Affected:= 9.1.0cu.2024_b20220329

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 web interface to confirm it is a TOTOLINK X18 router. Access the router's admin panel (typically at 192.168.0.1) and look for the model number in the status or system information page.
    Affected if The device is not a TOTOLINK X18 router, then this CVE does not apply.
  2. Check firmware version
    In the router's web admin panel, navigate to System or Status section to view the firmware version. Compare against the affected version 9.1.0cu.2024_b20220329.
    Affected if The installed firmware version is 9.1.0cu.2024_b20220329, then the device is directly affected by this vulnerability.
  3. Verify cgi-bin/cstecgi.cgi is accessible
    Attempt to access the CGI binary via HTTP/HTTPS request to the router (e.g., http://[router-ip]/cgi-bin/cstecgi.cgi). A response (even an error) indicates the web interface is active.
    Affected if The cgi-bin/cstecgi.cgi endpoint is reachable and responds to requests, the vulnerable binary is exposed.
  4. Determine WAN exposure
    Check router firewall settings to see if the web management interface (port 80/443) is accessible from the WAN/internet side. Look for 'Remote Management' or 'WAN Access' settings in the Administration or Security section.
    Affected if Remote management is enabled and the router is WAN-accessible, the vulnerability is remotely exploitable.
  5. Check for signs of exploitation
    Review router logs for unusual POST requests to cstecgi.cgi with abnormally large parameter lengths, especially those targeting password or configuration functions.
    Affected if Log evidence shows large or malformed requests to the cgi-bin/cstecgi.cgi endpoint, potential exploitation may have occurred.

A user is affected if they own a TOTOLINK X18 router running firmware version 9.1.0cu.2024_b20220329 with the web interface accessible, particularly if exposed to WAN.

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

Since the vendor has not responded to the disclosure, implement compensating controls: restrict remote access to the router's web interface via firewall rules, disable WAN-facing management if possible, and monitor for exploitation attempts. Replace the device with a supported model if the vendor does not release a firmware patch.

Fix this in X18 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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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-2025-1340 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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