CVE-2024-4247
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 has been found in Tenda i21 1.0.0.14(4656) and classified as critical. This vulnerability affects the function formQosManage_auto. The manipulation of the argument ssidIndex leads to stack-based buffer overflow. The attack can be initiated remotely. VDB-262138 is the identifier assigned to this vulnerability. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
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 confidenceA stack-based buffer overflow vulnerability exists in the formQosManage_auto function of Tenda i21 router firmware version 1.0.0.14(4656). The vulnerability is caused by insufficient bounds checking on the ssidIndex argument passed to the function, allowing an attacker to overflow a stack-allocated buffer. This can be exploited remotely, potentially leading to arbitrary code execution or 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= 1.0.0.14\(4656\)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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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.
-
Confirm Tenda i21 router modelCheck the device label or web interface status page to verify the model is Tenda i21Affected if Device is not a Tenda i21 router
-
Identify firmware versionAccess the router web interface (typically 192.168.0.1) and check the firmware version in System Settings or Status page, or use command 'cat /proc/version' via telnet/SSH if availableAffected if Firmware version is NOT exactly 1.0.0.14(4656)
-
Check web interface exposureVerify if the router's web management interface (port 80/443) is accessible from untrusted networks by reviewing firewall rules or network configurationAffected if Web interface is exposed to untrusted networks (internet)
-
Review for exploitation indicatorsCheck router logs for unusual formQosManage_auto requests, unexpected reboots, or unauthorized configuration changesAffected if Logs show unexpected requests to formQosManage function or abnormal router behavior
You are affected only if you have a Tenda i21 router running exactly firmware version 1.0.0.14(4656) with the web interface accessible to attackers.
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 dataRestrict network exposure of affected Tenda i21 devices and monitor for exploitation attempts. Since the vendor has not responded to disclosure, consider device replacement if no firmware update becomes available.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-4247 — 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-2024-4247 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data