Command InjectionWeakness · CWE-77

CVE-2026-7242

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-28
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
A vulnerability was determined in Totolink A8000RU 7.1cu.643_b20200521. Impacted is the function setOpenVpnClientCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Executing a manipulation of the argument enabled can lead to os command injection. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized.

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

The Totolink A8000RU router firmware 7.1cu.643_b20200521 contains an OS command injection vulnerability in the /cgi-bin/cstecgi.cgi CGI handler. The setOpenVpnClientCfg function fails to properly sanitize user input passed through the 'enabled' parameter, allowing remote unauthenticated attackers to execute arbitrary operating system commands on the device.

MitigationApply available firmware补丁 if released by Totolink; otherwise disable the OpenVPN client functionality, restrict administrative interface access to trusted networks, or implement network segmentation to limit exposure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
    Check the router label or web interface for the model number to confirm it is a Totolink A8000RU
    Affected if The device is not a Totolink A8000RU router - other models are not affected by this specific CVE
  2. Check the firmware version
    Log into the router web interface and look for the firmware version in the system status or administration settings, or use the command 'cat /proc/version' or 'nvram get firm_version' via telnet/ssh if available
    Affected if The firmware version is 7.1cu.643_b20200521 - this is the exact affected version
  3. Verify the vulnerable CGI endpoint exists
    Attempt to access http://<router-ip>/cgi-bin/cstecgi.cgi via HTTP request and check for a response
    Affected if The endpoint responds - confirms the CGI handler is present on the device
  4. Check if OpenVPN client feature is configured
    In the router web interface, navigate to the VPN or OpenVPN client settings section and look for any OpenVPN client configuration options
    Affected if OpenVPN client functionality is available/enabled on the device - the command injection occurs through the 'enabled' parameter of the setOpenVpnClientCfg function
  5. Verify web management interface exposure
    Check if the router's web interface (ports 80/443) is accessible from untrusted networks or the internet by testing remote connectivity to the CGI endpoint
    Affected if The router web interface is exposed to untrusted networks - remote unauthenticated attackers need network access to the cgi-bin/cstecgi.cgi endpoint

You are affected if you have a Totolink A8000RU router running firmware version 7.1cu.643_b20200521 with the OpenVPN client feature accessible from a network where untrusted users can reach the web interface.

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 available firmware补丁 if released by Totolink; otherwise disable the OpenVPN client functionality, restrict administrative interface access to trusted networks, or implement network segmentation to limit exposure.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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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-2026-7242 in production — separate from our analysis above.

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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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