CVE-2026-5679
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 security vulnerability has been detected in Totolink A3300R 17.0.0cu.557_B20221024. The impacted element is the function vsetTr069Cfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument stun_pass leads to os command injection. 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 confidenceOS command injection vulnerability in Totolink A3300R router firmware (v17.0.0cu.557_B20221024). The cstecgi.cgi binary's vsetTr069Cfg function fails to sanitize the stun_pass parameter before passing it to system(), allowing 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
- Adjacent
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:A/AC:L/PR:L/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 router modelAccess the router web interface or check the device label to confirm it is a Totolink A3300R modelAffected if The device is not a Totolink A3300R, then it is not affected by this specific CVE
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Check firmware versionLog into the router web interface and navigate to System > Firmware Upgrade or Status page to view the firmware version. Compare it to the affected version 17.0.0cu.557_B20221024Affected if The installed firmware version is 17.0.0cu.557_B20221024 or earlier within the same branch, indicating potential vulnerability
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Verify CGI binary existsAttempt to access the file /cgi-bin/cstecgi.cgi on the router (e.g., via HTTP GET request to http://<router-ip>/cgi-bin/cstecgi.cgi)Affected if The CGI binary responds or is accessible, confirming the attack surface exists
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Check web management accessDetermine if the router web interface is accessible from untrusted networks by examining NAT/firewall rules or by attempting to reach the router from an external IPAffected if The web management interface is exposed to untrusted networks, increasing the risk of exploitation since authentication is required for the attack
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Confirm authentication is enforcedVerify that the router requires valid credentials to access the cstecgi.cgi endpoint by attempting an unauthenticated requestAffected if The endpoint allows unauthenticated access, which would actually expand the attack surface beyond what the CVE description states (though the CVE notes authentication is required)
The device is affected if it is a Totolink A3300R running firmware version 17.0.0cu.557_B20221024 (or comparable vulnerable version in that branch) and the web management interface with the cstecgi.cgi endpoint is accessible, even though the CVE requires valid authentication credentials.
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 vendor firmware update when available. Until then, disable remote administration interfaces or place device behind a firewall with no WAN access. Monitor for indicators of compromise.
- Consultation6.0 h
- Implementation2.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-5679 — 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-2026-5679 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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