dbcve.org
Dir 816 FirmwareOperating system · Dlink

CVE-2025-5630

CRITICAL · 9.8 CVSS v3.1 Published 2025-06-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

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 · unedited
A vulnerability has been found in D-Link DIR-816 1.10CNB05 and classified as critical. This vulnerability affects unknown code of the file /goform/form2lansetup.cgi. The manipulation of the argument ip 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 confidence

A stack-based buffer overflow vulnerability exists in D-Link DIR-816 router firmware 1.10CNB05 within the /goform/form2lansetup.cgi handler. The 'ip' parameter is not properly bounds-checked before being copied to a fixed-size stack buffer, allowing remote attackers to overflow the stack and potentially achieve remote code execution.

MitigationThis is a critical severity buffer overflow in an end-of-life product receiving no vendor support. Since no firmware patch exists, immediate mitigation requires decomissioning affected devices and replacing with supported hardware, or implementing strict network access controls to prevent external access to the router's management interface.

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
Dir 816 FirmwareOperating system
Affected:= 1.10cnb05

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device model is D-Link DIR-816
    Access the router's web management interface and check the device info page, or check the device label/sticker for the model number
    Affected if Device is not a D-Link DIR-816 router
  2. Check firmware version is 1.10CNB05
    In the router's web UI, navigate to System > Firmware Upgrade or Status page to view the firmware version. Alternatively, check the vendor download page or the firmware file name if you have access to the firmware binary
    Affected if Firmware version is 1.10CNB05 exactly
  3. Determine if router management interface is network-accessible
    Check if the router's web UI (typically on ports 80 or 443) is exposed to untrusted networks such as the internet. Scan external IP addresses or review firewall rules for port 80/443 open to WAN
    Affected if The /goform/form2lansetup.cgi endpoint is reachable from untrusted networks (e.g., internet-facing)
  4. Verify the LAN setup form is functional
    Attempt to access /goform/form2lansetup.cgi on the router (requires authentication). The vulnerability exists in the 'ip' parameter handling within this handler
    Affected if The form2lansetup.cgi endpoint exists and accepts the 'ip' parameter without proper bounds checking

A user is affected if they operate a D-Link DIR-816 router running firmware version 1.10CNB05 with the management interface exposed to untrusted networks.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

This is a critical severity buffer overflow in an end-of-life product receiving no vendor support. Since no firmware patch exists, immediate mitigation requires decomissioning affected devices and replacing with supported hardware, or implementing strict network access controls to prevent external access to the router's management interface.

Recommended fix High confidence
  1. Replace the end-of-life D-Link DIR-816 with a currently supported router model from D-Link or another vendor
  2. If immediate replacement is not possible, isolate the device on a separate network segment behind a firewall with strict inbound access controls
  3. Disable remote management interfaces if not absolutely necessary
  4. Monitor for any vendor advisories (though unlikely for EOL products)
Caveat Device replacement required - D-Link has stated this product is no longer supported and no firmware patch is available

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Dir 816 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-5630 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-5630 in production — separate from our analysis above.

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.

What this is

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.

What belongs here
  • 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