dbcve.org
Dir 806a FirmwareOperating system · Dlink

CVE-2025-15391

CRITICAL · 9.8 CVSS v3.1 Published 2025-12-31
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 weakness has been identified in D-Link DIR-806A 100CNb11. Affected is the function ssdpcgi_main of the component SSDP Request Handler. This manipulation causes command injection. The attack can be initiated remotely. The exploit has been made available to the public and could be exploited. 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

Command injection vulnerability in the SSDP Request Handler (ssdpcgi_main function) of D-Link DIR-806A 100CNb11 routers allows remote attackers to execute arbitrary operating system commands via specially crafted SSDP requests.

MitigationSince the product is end-of-life and no longer supported by D-Link, replace affected devices with currently supported models; as interim mitigation, network segmentation and blocking SSDP traffic at the perimeter can reduce attack surface.

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 806a FirmwareOperating system
Affected:= 100cnb11

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. Identify the router model
    Check the device label or web interface for the exact model number (DIR-806A)
    Affected if The model is D-Link DIR-806A and the firmware version is 100cnb11
  2. Check the installed firmware version
    Access the router web interface (usually at 192.168.0.1) and navigate to Status or System settings to view the firmware version; alternatively, check via CLI if telnet/ssh is enabled
    Affected if The firmware version displayed is exactly 100cnb11
  3. Verify if SSDP/UPnP service is enabled
    Log into the router web interface and look for SSDP, UPnP, or Internet Gateway Device (IGD) settings under Advanced or Network settings
    Affected if SSDP/UPnP is enabled on the device (the vulnerable ssdpcgi_main function processes SSDP requests)
  4. Check network exposure of the router management interface
    Determine if the router's web interface (port 80/443) is accessible from outside the local network by testing remote connectivity to the WAN IP on HTTP/HTTPS ports
    Affected if The router management interface is directly accessible from the internet (WAN-side)

You are affected if you have a D-Link DIR-806A router running firmware version 100cnb11 with SSDP/UPnP enabled and especially if the device is internet-facing.

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

Since the product is end-of-life and no longer supported by D-Link, replace affected devices with currently supported models; as interim mitigation, network segmentation and blocking SSDP traffic at the perimeter can reduce attack surface.

Recommended fix High confidence
  1. This vulnerability affects D-Link DIR-806A firmware version 100CNb11, which D-Link has explicitly stated is no longer supported.
  2. The vendor (D-Link) does not provide security updates for this end-of-life product.
  3. There is no official firmware patch available from D-Link for this vulnerability.
  4. Consider replacing the affected device with a currently supported model that receives regular security updates.
  5. If replacement is not immediately possible, consider network-level mitigations such as blocking SSDP (port 1900) traffic from untrusted networks at the firewall.
Caveat This is an end-of-life device with no vendor support; no upgrade path exists. The device should be retired and replaced.

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

Fix this in Dir 806a Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing1.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,270
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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-2025-15391 in production — separate from our analysis above.

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What this is

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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