dbcve.org
Dir 816 FirmwareOperating system · Dlink

CVE-2025-5622

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 was found in D-Link DIR-816 1.10CNB05 and classified as critical. Affected by this issue is the function wirelessApcli_5g of the file /goform/wirelessApcli_5g. The manipulation of the argument apcli_mode_5g/apcli_enc_5g/apcli_default_key_5g leads to stack-based buffer overflow. The attack may be launched 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

Stack-based buffer overflow in the D-Link DIR-816 router's wirelessApcli_5g web form handler allows remote attackers to execute arbitrary code via crafted HTTP requests manipulating apcli_mode_5g, apcli_enc_5g, or apcli_default_key_5g parameters. The vulnerable function processes user input without proper bounds checking, overwriting stack memory.

MitigationSince this is an end-of-life device with no vendor patch available, replace the affected D-Link DIR-816 with a currently-supported router. If immediate replacement is not feasible, isolate the device on a restricted network segment and disable remote management interfaces to 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 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. Identify the device model
    Check the device label on the router or log into the web interface and look for the model name on the status or administration page
    Affected if Device is not a D-Link DIR-816 router
  2. Check the firmware version
    Log into the router web interface, navigate to Status or Administration > Firmware/Upgrade page to view the current firmware version. Alternatively, access via CLI if telnet/ssh is enabled and run 'cat /proc/version' or check /etc/version
    Affected if Firmware version is 1.10cnb05
  3. Determine if the web management interface is exposed
    Check router WAN IP accessibility by attempting to access http://[WAN-IP] from an external network, or review port forwarding/firewall rules on upstream devices. Use 'nmap [WAN-IP] -p 80,443' or similar to check if HTTP/HTTPS ports are open to the internet
    Affected if The router's web interface (port 80/443) is accessible from the WAN/internet side
  4. Check if 5G wireless client mode is configured
    Log into the web interface and navigate to Wireless Settings > Advanced or Wireless > AP Client mode. Look for settings involving apcli_mode_5g, apcli_enc_5g, or apcli_default_key_5g. The vulnerability triggers when these 5G AP client parameters are present in the web form
    Affected if 5G wireless AP client mode is enabled or configurable in the wireless settings

You are affected if you have a D-Link DIR-816 router running firmware 1.10cnb05 with its web interface accessible and the 5G wireless AP client feature is present in the web form.

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 this is an end-of-life device with no vendor patch available, replace the affected D-Link DIR-816 with a currently-supported router. If immediate replacement is not feasible, isolate the device on a restricted network segment and disable remote management interfaces to reduce attack surface.

Recommended fix High confidence
  1. 1. This vulnerability affects D-Link DIR-816 firmware version 1.10CNB05, which is explicitly stated as a product no longer supported by the maintainer.
  2. 2. As the product is end-of-life, no official security patches or firmware updates are available from D-Link.
  3. 3. Implement network segmentation to isolate the affected device on a restricted VLAN separate from critical business systems.
  4. 4. If possible, replace the end-of-life D-Link DIR-816 with a currently supported router from a vendor that provides regular security updates.
  5. 5. If the device must remain in service, disable the wirelessApcli_5g functionality if not required, and monitor network traffic for indicators of exploitation attempts.
Caveat No upgrade path available as the product is end-of-life and no longer supported by D-Link

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

Fix this in Dir 816 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing2.0 h
  • Review / QA1.0 h
12.0 hours of engineering $2,160
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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-2025-5622 in production — separate from our analysis above.

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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