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Command InjectionWeakness · CWE-77

CVE-2026-5978

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-09
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 security vulnerability has been detected in Totolink A7100RU 7.4cu.2313_b20191024. Affected is the function setWiFiAclRules of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument mode leads to os command injection. The attack can be initiated remotely. The exploit has been disclosed publicly 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 · moderate confidence

OS command injection vulnerability in Totolink A7100RU router firmware 7.4cu.2313_b20191024. The setWiFiAclRules function in /cgi-bin/cstecgi.cgi does not properly sanitize the mode parameter, allowing remote attackers to inject and execute arbitrary OS commands on the device.

MitigationApply vendor firmware patch if available; otherwise restrict administrative interface access to trusted networks only or replace the device.

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
    Access the router admin web interface and check the status or system info page for the model name, or physically inspect the device label.
    Affected if The device is not a Totolink A7100RU router.
  2. Check the firmware version
    In the router admin interface, navigate to System > Firmware Upgrade or Status page and record the firmware version string displayed.
    Affected if The firmware version is 7.4cu.2313_b20191024.
  3. Verify the CGI endpoint exists
    Send an HTTP request to http://[router-ip]/cgi-bin/cstecgi.cgi and check for a valid response (any response indicates the endpoint is present).
    Affected if The endpoint returns any HTTP response, confirming cstecgi.cgi is accessible.
  4. Confirm WiFi ACL functionality is exposed
    Check the router admin interface for WiFi settings > WiFi ACL (Access Control List) or similar wireless security configuration section. If the feature exists and is accessible in the UI, the vulnerable function can be triggered.
    Affected if WiFi ACL feature is present and accessible in the router admin interface.

A user is affected if they have a Totolink A7100RU router running firmware version 7.4cu.2313_b20191024 with the /cgi-bin/cstecgi.cgi endpoint accessible and WiFi ACL 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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware patch if available; otherwise restrict administrative interface access to trusted networks only or replace the device.

Have this fixed 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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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-2026-5978 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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