CVE-2024-6143
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 · uneditedActiontec WCB6200Q uh_tcp_recv_header Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Actiontec WCB6200Q routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the HTTP server. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length buffer. An attacker can leverage this vulnerability to execute code in the context of the HTTP server. Was ZDI-CAN-21414.
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 confidenceBuffer overflow in the HTTP server's uh_tcp_recv_header function allows network-adjacent attackers to execute arbitrary code via specially crafted HTTP requests. The vulnerability stems from insufficient validation of user-supplied data length before copying into a fixed-size buffer, enabling overflow and RCE in the context of the HTTP server without authentication.
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= 1.2l.03.5CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:A/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 device modelAccess the device admin interface or check the device label to confirm the model is Actiontec Wcb6200qAffected if Device is not an Actiontec Wcb6200q
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Check firmware versionNavigate to the device admin panel (typically 192.168.0.1 or 192.168.1.1), look in Status, System, or About section for firmware version information. Alternatively, check via telnet/SSH if enabled or examine firmware file metadata.Affected if Firmware version is 1.2l.03.5 exactly
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Verify HTTP server is enabledCheck device settings for HTTP server or web management interface status. This is typically found under Management, Administration, or Remote Access settings.Affected if HTTP server is enabled on the device
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Confirm network exposureDetermine if the HTTP management interface is accessible from the WAN/internet side or from the LAN side by checking firewall rules, port forwarding settings, or remote management enable/disable status.Affected if HTTP service is reachable from network-adjacent locations (WAN or untrusted network)
A user is affected if they have an Actiontec Wcb6200q device running firmware version 1.2l.03.5 with the HTTP server enabled and accessible from a network-adjacent attack surface.
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 available firmware updates from Actiontec; if unavailable, restrict network access to the device's HTTP service via firewall rules or disable remote management interfaces.
- Consultation12.0 h
- Implementation32.0 h
- Testing16.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-6143 — 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-2024-6143 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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