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Command InjectionWeakness · CWE-77

CVE-2026-9454

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-25
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 flaw has been found in Totolink A8000RU 7.1cu.643_b20200521. This vulnerability affects the function setOpenVpnCertGenerationCfg of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. Executing a manipulation of the argument servername can lead to os command injection. The attack may be launched 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

OS command injection vulnerability in Totolink A8000RU router's web management interface. The setOpenVpnCertGenerationCfg function in /cgi-bin/cstecgi.cgi fails to properly sanitize the servername argument, allowing remote attackers to inject and execute arbitrary OS commands via the CGI interface.

MitigationApply vendor firmware patch when available; if no patch exists, disable the OpenVPN certificate generation feature or implement network segmentation to restrict access to the web management interface.

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 access the web management interface to confirm the model is Totolink A8000RU
    Affected if Device model is Totolink A8000RU
  2. Check the firmware version
    Access the router web interface (usually at 192.168.0.1) and navigate to System Status or Firmware Upgrade page to view the current firmware version. Compare against 7.1cu.643_b20200521
    Affected if Firmware version is 7.1cu.643_b20200521 or earlier without the patch
  3. Verify cstecgi.cgi is present
    Attempt to access /cstecgi.cgi on the router's web server (e.g., http://192.168.0.1/cstecgi.cgi). A 200 OK response or the binary existing indicates the vulnerable component is present
    Affected if The cstecgi.cgi binary is accessible on the web interface
  4. Confirm OpenVPN feature is enabled
    Log into the router web interface and check if OpenVPN or VPN certificate generation settings are present and enabled in the VPN or Advanced settings section
    Affected if OpenVPN certificate generation functionality is accessible or enabled on the device

Your Totolink A8000RU router is affected if it runs firmware 7.1cu.643_b20200521, has the cstecgi.cgi interface accessible, and has OpenVPN certificate generation features available.

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; if no patch exists, disable the OpenVPN certificate generation feature or implement network segmentation to restrict access to the web management interface.

Have this fixed 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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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-2026-9454 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