dbcve.org
G416 FirmwareOperating system · Dlink

CVE-2023-50209

HIGH · 8.8 CVSS v3.1 Published 2024-05-03
Fix available
A fix is available. Upgrade to 1.09b01 or later.
See remediation →
93/100
Remediation priority · Urgent
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
D-Link G416 cfgsave Stack-Based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link G416 wireless routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the HTTP service listening on TCP port 80. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a fixed-length stack-based buffer. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-21442.

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 cfgsave function of D-Link G416 routers. The HTTP service on port 80 fails to validate input length before copying user-supplied data to a fixed-size stack buffer, allowing unauthenticated network-adjacent attackers to achieve root-level code execution.

MitigationApply the vendor-supplied firmware update from D-Link. If no update is available, restrict network access to the router's management interface to trusted sources only.

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
G416 FirmwareOperating system
Affected:< 1.09b01

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/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 access the router's web interface and look for the model number (usually displayed on the status page or in the header)
    Affected if The model is D-Link G416 and the vulnerability applies only to this specific model
  2. Check the installed firmware version
    Access the router's web interface and navigate to the Status or Management page to view the firmware version. Alternatively, use the command 'cat /proc/version' or check the firmware file name if you have shell access
    Affected if The firmware version is lower than 1.09b01 (for example, 1.08 or earlier)
  3. Verify the HTTP service is enabled
    Attempt to access http://<router-ip>/ in a web browser or use 'curl http://<router-ip>/' from a command line
    Affected if The HTTP service on port 80 responds and is accessible (the vulnerability requires this service to be running)
  4. Check if the cfgsave endpoint is accessible
    Attempt to access http://<router-ip>/cfgsave or check for the cfgsave CGI binary on the device using 'ls /www/cgi-bin/cfgsave' if shell access is available
    Affected if The cfgsave function endpoint exists and responds to requests (this is the vulnerable component)

You are affected if you have a D-Link G416 router with firmware version below 1.09b01 and the HTTP service on port 80 is enabled and accessible.

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
Upgrade available Upgrade to 1.09b01 or later
Fixed in 1.09b01
Interim mitigation

Apply the vendor-supplied firmware update from D-Link. If no update is available, restrict network access to the router's management interface to trusted sources only.

Recommended fix High confidence

G416 Firmware 1.09b01 or later

  1. Download the G416 firmware version 1.09b01 or later from D-Link's official support website (support.dlink.com)
  2. Log into the D-Link G416 router web interface via HTTP/HTTPS on the local network
  3. Navigate to the Administration or System Settings section
  4. Locate the Firmware Upgrade or Upload Firmware option
  5. Upload the downloaded firmware file and wait for the upgrade process to complete
  6. After the router reboots, verify the firmware version has been updated

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

Fix this in G416 Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

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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-2023-50209 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