- Close the port if nothing on the host needs it.
- Identify the process that listens on it (commands below) before opening it in a firewall.
- Expose a service only to the networks that use it.
Port 4366: ShadowStream System
Port 4366 is assigned by IANA to shadowstream (ShadowStream System).
How shadowstream works
Other servicesThe client sends a request to port 4366 and the shadowstream service answers.
- Transport
- UDP
- Exposure risk
- not rated depends on the program listening
- Encryption
- Unknownnot stated by the registry
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Other services
Is port 4366 dangerous?
We have no specific security note for port 4366. Its risk depends on the program actually listening on it. General advice for other services services:
IANA registry entries for port 4366
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| shadowstream | 4366 | UDP | ShadowStream System | - | 2014-12-17 |
| - | 4366 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 4366, and is it reachable?
Linux
sudo ss -ltnup 'sport = :4366' # process listening on 4366
sudo lsof -nP -i :4366macOS
sudo lsof -nP -i :4366
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 4366 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 4366 netstat -ano | findstr :4366
From another machine
nmap -p 4366 -sV <host> sudo nmap -sU -p 4366 <host> nc -zv <host> 4366
Block it in the firewall
sudo ufw deny 4366/udp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 4366" -Direction Inbound -LocalPort 4366 -Protocol UDP -Action Block # Windows
What is port 4366 used for?
Port 4366 is assigned by IANA to shadowstream (ShadowStream System).
Is port 4366 TCP or UDP?
Port 4366 is registered for UDP.
Is it safe to open port 4366?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Close the port if nothing on the host needs it.
How do I check if port 4366 is open?
On Linux run "ss -ltnup 'sport = :4366'", on macOS "lsof -nP -i :4366", and on Windows "netstat -ano | findstr :4366" to see the local process. From another machine, "nmap -p 4366 <host>" shows whether it is reachable.