CVE-2021-45994
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 · uneditedTenda routers G1 and G3 v15.11.0.17(9502)_CN were discovered to contain a stack overflow in the function formDelDhcpRule. This vulnerability allows attackers to cause a Denial of Service (DoS) via the delDhcpIndex parameter.
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 confidenceA stack buffer overflow vulnerability exists in the formDelDhcpRule function of Tenda G1 and G3 routers (firmware v15.11.0.17). The vulnerability is triggered via the delDhcpIndex HTTP parameter, allowing an attacker to overflow the stack and cause a Denial of Service.
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= 15.11.0.17\(9502\)_cn= 15.11.0.17\(9502\)_cnCVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 router modelAccess the router's web administration interface or check the device label to confirm it is a Tenda G1 or G3 router.Affected if The device is not a Tenda G1 or G3 router, then it is not affected by this CVE.
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Check firmware versionLog into the router's web interface and navigate to the System Status or Firmware Version page. Alternatively, check the firmware file name or version displayed in the admin panel.Affected if The firmware version is exactly 15.11.0.17(9502)_cn - only this specific version is affected. Other versions are not within the affected range.
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Verify HTTP administration interface is accessibleAttempt to access the router's web interface via HTTP on the default IP (commonly 192.168.0.1 or 192.168.1.1). Confirm the login page loads.Affected if The delDhcpIndex parameter is processed by the formDelDhcpRule function through the HTTP interface - if the web interface is disabled or not accessible, the attack surface is reduced.
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Confirm DHCP management feature is exposedLocate the DHCP settings section in the router's web interface. Check if there is a DHCP rule management or deletion function available.Affected if The vulnerability exists in the formDelDhcpRule function which handles DHCP rule deletion - the feature must be present and accessible for the flaw to be exploitable.
You are affected only if you have a Tenda G1 or G3 router running firmware version 15.11.0.17(9502)_cn with the HTTP administrative interface and DHCP management feature accessible.
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, restrict administrative interface access to trusted networks to prevent unauthenticated exploitation of this overflow.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-45994 — 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-2021-45994 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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