CVE-2026-31181
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 · uneditedAn issue was discovered in ToToLink A3300R firmware v17.0.0cu.557_B20221024 allowing attackers to execute arbitrary commands via the stunServerAddr parameter to /cgi-bin/cstecgi.cgi.
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. Attackers can execute arbitrary operating system commands by injecting shell metacharacters into the stunServerAddr parameter when calling the /cgi-bin/cstecgi.cgi endpoint, likely due to unsanitized user input being passed to a system() or similar function.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 17.0.0cu.557_b20221024CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify the device modelCheck the router label or access the web interface to confirm the device is a ToToLink A3300R modelAffected if The device is not a ToToLink A3300R router
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Check the firmware versionAccess the router web administration panel, typically at the default IP (e.g., 192.168.0.1 or 192.168.1.1), and navigate to System Status or Firmware Upgrade to view the installed firmware version. Alternatively, check the build date in the firmware filename if you have firmware backup access.Affected if The firmware version is 17.0.0cu.557_b20221024
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Verify the CGI endpoint is accessibleAttempt to access http://<router_ip>/cgi-bin/cstecgi.cgi from within the local network. A response (even an error) indicates the CGI interface is active.Affected if The CGI endpoint responds, indicating it is enabled and reachable
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Confirm the stunServerAddr parameter is processedSend a crafted request to the CGI endpoint with the stunServerAddr parameter (e.g., via curl: curl -X POST http://<router_ip>/cgi-bin/cstecgi.cgi -d 'topicurl=stun&stunServerAddr=test'). Observe if the parameter is processed and reflected in the response.Affected if The parameter is accepted and processed by the CGI binary without sanitization validation
A user is affected if they are running ToToLink A3300R firmware version 17.0.0cu.557_b20221024 with the web CGI interface accessible and the stunServerAddr parameter functional.
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 dataUpdate to a patched firmware version if available. If no update exists, disable remote administration, restrict management interface access to trusted networks only, and consider replacing the end-of-life device.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-31181 — 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-2026-31181 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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- 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
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