CVE-2026-5689
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 · uneditedA vulnerability was detected in Totolink A7100RU 7.4cu.2313_b20191024. The affected element is the function setNtpCfg of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument tz results in os command injection. Remote exploitation of the attack is possible. The exploit is now public 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 confidenceOS command injection vulnerability in the setNtpCfg function of /cgi-bin/cstecgi.cgi on Totolink A7100RU router firmware 7.4cu.2313_b20191024. The 'tz' (timezone) parameter is not properly sanitized before being passed to a system call, allowing authenticated remote attackers to execute arbitrary OS commands.
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
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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 checksWork through these to decide whether this CVE applies to you.
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Identify the device modelCheck the device label or admin web interface for the exact model number to confirm it is a Totolink A7100RU routerAffected if The device is not a Totolink A7100RU model
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Determine the firmware versionLog into the router admin interface (typically at 192.168.0.1 or 192.168.1.1) and check the firmware version under System or Administration settings, or use the grep command on the firmware binary if you have a copyAffected if The firmware version is within the affected range and no patch has been applied
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Verify web interface accessibilityAttempt to access the router login page via HTTP/HTTPS from the network. Check if port 80 or 443 is open and respondingAffected if The web interface (cgi-bin/cstecgi.cgi) is directly accessible from untrusted networks (such as the internet)
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Confirm NTP configuration endpoint existsSend a GET or POST request to /cgi-bin/cstecgi.cgi and check if the setNtpCfg function is present. This can be done by reviewing the firmware binary for the string 'setNtpCfg' or observing API responsesAffected if The setNtpCfg function endpoint is present and accepts the 'tz' parameter without sanitization
A user is affected if they have a Totolink A7100RU router with a vulnerable firmware version where the web interface is exposed to network access, allowing the timezone parameter in the NTP configuration to be manipulated for command injection.
Generated from the published advisory. Verify against your own configuration.
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 dataApply available firmware vendor patch; if unavailable, isolate affected devices behind restrictive firewall rules or place in isolated network segments to limit exposure to unauthenticated attackers.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-5689 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-5689 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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