CyberHunter
Local dataset, no network
// Other services

Port 4123: Z-Wave Protocol

Port 4123 is assigned by IANA to z-wave (Z-Wave Protocol).

4123

How z-wave works

Other services
client:4123z-waveresponse client:4123z-waveresponse

The client sends a request to port 4123 and the z-wave service answers.

Transport
TCP · 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
01 Security

Is port 4123 dangerous?

We have no specific security note for port 4123. Its risk depends on the program actually listening on it. General advice for other services services:

  • 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.
02 Registry

IANA registry entries for port 4123

ServicePortTransportDescriptionReferenceUpdated
z-wave 4123 TCP, UDP Z-Wave Protocol - 2012-11-08

// source: IANA service name and port number registry

03 Check it

Which program uses port 4123, and is it reachable?

Linux

sudo ss -ltnup 'sport = :4123'      # process listening on 4123
sudo lsof -nP -i :4123

macOS

sudo lsof -nP -i :4123

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 4123 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 4123
netstat -ano | findstr :4123

From another machine

nmap -p 4123 -sV <host>
sudo nmap -sU -p 4123 <host>
nc -zv <host> 4123

Block it in the firewall

sudo ufw deny 4123/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 4123" -Direction Inbound -LocalPort 4123 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 4123 used for?

Port 4123 is assigned by IANA to z-wave (Z-Wave Protocol).

Is port 4123 TCP or UDP?

Port 4123 is registered for TCP and UDP.

Is it safe to open port 4123?

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 4123 is open?

On Linux run "ss -ltnup 'sport = :4123'", on macOS "lsof -nP -i :4123", and on Windows "netstat -ano | findstr :4123" to see the local process. From another machine, "nmap -p 4123 <host>" shows whether it is reachable.

05 Related
:4444 Metasploit default / krb524 tcp · udp · high risk :31337 Back Orifice / elite tcp · udp · high risk :1 TCP Port Service Multiplexer tcp · udp :5 Remote Job Entry tcp · udp :9 Discard tcp · udp · sctp · dccp :11 Active Users tcp · udp :17 Quote of the Day tcp · udp :18 Message Send Protocol (historic) tcp · udp

Latest vulnerability news

All news