CyberHunter
LinkedIn profile - Bastien Cordier Email: contact@bastiencordier.pro
// Other services

Port 538: gdomap

Port 538 is assigned by IANA to gdomap (gdomap).

538

How gdomap works

Other services
client:538gdomapresponse client:538gdomapresponse

The client sends a request to port 538 and the gdomap 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
Well-known (0-1023)
Category
Other services
01 Security

Is port 538 dangerous?

We have no specific security note for port 538. 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 538

ServicePortTransportDescriptionReferenceUpdated
gdomap 538 TCP, UDP gdomap - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 538, and is it reachable?

Linux

sudo ss -ltnup 'sport = :538'      # process listening on 538
sudo lsof -nP -i :538

macOS

sudo lsof -nP -i :538

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 538 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 538
netstat -ano | findstr :538

From another machine

nmap -p 538 -sV <host>
sudo nmap -sU -p 538 <host>
nc -zv <host> 538

Block it in the firewall

sudo ufw deny 538/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 538" -Direction Inbound -LocalPort 538 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 538 used for?

Port 538 is assigned by IANA to gdomap (gdomap).

Is port 538 TCP or UDP?

Port 538 is registered for TCP and UDP.

Is it safe to open port 538?

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 538 is open?

On Linux run "ss -ltnup 'sport = :538'", on macOS "lsof -nP -i :538", and on Windows "netstat -ano | findstr :538" to see the local process. From another machine, "nmap -p 538 <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