CVE-2024-5294
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 · uneditedD-Link DIR-3040 prog.cgi websSecurityHandler Memory Leak Denial-of-Service Vulnerability. This vulnerability allows network-adjacent attackers to create a denial-of-service condition on affected installations of D-Link DIR-3040 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the prog.cgi program, which handles HNAP requests made to the lighttpd webserver listening on ports 80 and 443. The issue results from the lack of proper memory management when processing HTTP cookie values. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. . Was ZDI-CAN-21668.
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 confidenceThe vulnerability exists in the prog.cgi program of D-Link DIR-3040 routers, specifically in the websSecurityHandler function that processes HNAP (Home Network Administration Protocol) requests. The flaw stems from improper memory management when parsing HTTP cookie values, causing a memory leak that eventually leads to denial of service. Since no authentication is required and the affected service listens on standard HTTP/HTTPS ports (80/443), network-adjacent attackers can repeatedly send specially crafted cookie values to exhaust system memory.
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= 120b03CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:A/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 the device modelAccess the router web interface or check the device label/marketing material to confirm the model is D-Link DIR-3040Affected if The device is not a D-Link DIR-3040 router, then this CVE does not apply
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Check the installed firmware versionLog into the router web interface and navigate to the Status or Management page to view the firmware version, or use the command 'grep version /proc/mtd' if SSH/Telnet access is availableAffected if The firmware version is exactly 120b03, then the device is affected by this vulnerability
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Verify if remote HTTP/HTTPS management is enabledCheck the router web interface under Remote Management or Access Control settings to determine if the web management interface is accessible on WAN ports 80/443Affected if Remote management is enabled and the web interface is accessible from the network (not just LAN), the attack surface exists for network-adjacent attackers
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Monitor for signs of memory exhaustion or service instabilityIf SNMP or syslog is configured, monitor for out-of-memory events, unexpected reboots, or prog.cgi process crashes. On the router CLI, check 'cat /proc/meminfo' for abnormally low available memory over timeAffected if The device exhibits repeated memory exhaustion, unexplained reboots, or prog.cgi service failures, this may indicate active exploitation of this memory leak vulnerability
The device is affected if it is a D-Link DIR-3040 router running firmware version 120b03 with its web management interface (ports 80/443) exposed to network-adjacent 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 dataApply available firmware patches from D-Link. If no patch exists, consider network segmentation to limit exposure to trusted users, or disable remote management interfaces if acceptable.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-5294 — 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-2024-5294 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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