Port 5900 — Virtual Network Computing (VNC): What It Is and When to Close It

Port 5900 is used by Virtual Network Computing (VNC). Remote desktop protocol that works cross-platform. Provides graphical access to desktops across operating systems.

What Does an Open Port 5900 Mean?

A VNC server is accessible. VNC has historically had weak authentication and many implementations have known vulnerabilities. Never expose VNC to the internet without a VPN tunnel.

This port should NOT be open to the public internet on typical systems. If you see it open, investigate immediately.

Security Risk Level

High Risk

How to Check if Port 5900 Is Open

Use the ExamineIP Port Scanner to check if port 5900 is open on any IP address from the public internet. Enter the target IP and select the relevant port preset.

How to Close Port 5900

  • Stop the service using port 5900 if you no longer need it
  • Add a firewall rule blocking inbound connections on port 5900
  • Check your router for port forwarding rules that expose this port
  • Run netstat -ano | findstr :5900 (Windows) to see which process is using it

Related Ports

VNC is related to: {implode(‘, ‘, Array)}

Protect Your Open Ports

If you need services like remote access, use a VPN to create a private encrypted tunnel instead of exposing ports directly to the internet. A VPN also hides your real IP address so port scanners cannot identify your device. Try PureVPN or IPVanish.

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