CVE-2025-6334
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 D-Link DIR-867 1.0 and classified as critical. This vulnerability affects the function strncpy of the component Query String Handler. The manipulation leads to stack-based buffer overflow. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.
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-based buffer overflow vulnerability exists in the D-Link DIR-867 1.0 router firmware's Query String Handler component. The use of the strncpy function to process query string parameters allows an attacker to overflow a stack-allocated buffer by providing an overly long input string, potentially enabling remote code execution.
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= 1.0CVSS 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.
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Confirm device model is D-Link DIR-867Log into the router web interface or check the device label/packaging to verify the exact model number. Alternatively, use an Nmap scan or check DHCP fingerprint information to identify the device.Affected if The device is not a D-Link DIR-867 router, then it is not affected by this specific CVE.
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Identify the installed firmware versionAccess the router web management interface and navigate to the Status or Firmware Upgrade page to view the current firmware version. On many D-Link devices, this can also be obtained via the /info.htm endpoint or by checking the system log.Affected if The firmware version is NOT 1.0, then the device may not be affected (this CVE specifically targets version 1.0).
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Verify the Query String Handler is accessibleConfirm the router web interface is enabled and accessible on the default HTTP port (80) or HTTPS port (443). The vulnerability exists in the Query String Handler component which processes URL query parameters.Affected if The web management interface is disabled or not accessible, the vulnerability cannot be triggered remotely.
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Check network exposure of management interfaceDetermine if the router management interface is exposed to untrusted networks by reviewing firewall rules, port forwarding configurations, or performing an external port scan targeting ports 80/443.Affected if The management interface is exposed to the internet or untrusted networks, the device is at higher risk of being exploited via this vulnerability.
The device is affected if it is a D-Link DIR-867 router running firmware version 1.0 and its web management interface (Query String Handler) is accessible to an attacker.
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.
dbcve · scopedSince D-Link no longer supports the DIR-867, no official firmware patch will be released. Organizations should retire and replace affected devices. If immediate replacement is impossible, restrict network access to the device's management interface to reduce exposure.
Replace with a currently supported router model. D-Link DIR-867 is end-of-life with no further firmware updates.
- 1. Immediately isolate the affected D-Link DIR-867 device from untrusted networks by placing it behind a properly configured firewall or NAT gateway.
- 2. Disable remote management features (web UI access from WAN) if enabled, as the vulnerability is remotely exploitable.
- 3. Limit access to the device's management interface to only trusted internal IP addresses.
- 4. Monitor for any suspicious activity or unauthorized access attempts.
- 5. Since D-Link DIR-867 firmware 1.0 is end-of-life and no longer supported, strongly consider replacing the device with a currently supported model from D-Link or another vendor.
- 6. If replacement is not immediately possible, apply network-level filtering to block external attackers from reaching the vulnerable service.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation24.0 h
- Testing12.0 h
- Review / QA8.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2025-6334 — 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-2025-6334 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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