CVE-2026-5677
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 flaw has been discovered in Totolink A7100RU 7.4cu.2313_b20191024. Impacted is the function CsteSystem of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument resetFlags results in os command injection. The attack may be initiated remotely. The exploit has been released to the public and may be used for attacks.
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 Totolink A7100RU router firmware 7.4cu.2313_b20191024. The CsteSystem function in /cgi-bin/cstecgi.cgi does not properly sanitize the resetFlags parameter before passing it to a system call, 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
- 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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Confirm device model is Totolink A7100RUAccess the router web interface and check the status or system info page for the model name, or log into the admin panel and look for the device model identifier in the firmware/version sectionAffected if The device is not a Totolink A7100RU router
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Check installed firmware versionLog into the router web admin panel and navigate to System or Status section to view the firmware version. Compare this version string to 7.4cu.2313_b20191024Affected if The installed firmware version matches or predates 7.4cu.2313_b20191024
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Verify the vulnerable CGI endpoint existsAttempt to access http://<router-ip>/cgi-bin/cstecgi.cgi via HTTP request. A 403 or similar HTTP response indicates the file exists on the deviceAffected if The file /cgi-bin/cstecgi.cgi is present on the device
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Check if remote web management is accessibleDetermine if the router web interface is reachable from outside the local network by testing HTTP access to the router IP from a remote location, or check the router firewall settings for allowed management sourcesAffected if The web management interface is exposed to untrusted networks or the internet
A user is affected if they are running Totolink A7100RU firmware version 7.4cu.2313_b20191024 or earlier with the cstecgi.cgi endpoint present and remote web management enabled.
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 patch when available; if no patch exists, restrict network access to the device's management interface or consider device replacement. Implement input validation and avoid passing user-controlled parameters to shell commands.
- Consultation4.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-5677 — 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-2026-5677 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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