CyberHunter
// Other services

Port 3392: EFI License Management

Port 3392 is assigned by IANA to efi-lm (EFI License Management).

3392

How efi-lm works

Other services
client:3392efi-lmresponse client:3392efi-lmresponse

The client sends a request to port 3392 and the efi-lm 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)
01 Security

Is port 3392 dangerous?

We have no specific security note for port 3392. 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 3392

ServicePortTransportDescriptionReferenceUpdated
efi-lm 3392 TCP, UDP EFI License Management - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 3392, and is it reachable?

Linux

sudo ss -ltnup 'sport = :3392'      # process listening on 3392
sudo lsof -nP -i :3392

macOS

sudo lsof -nP -i :3392

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 3392 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 3392
netstat -ano | findstr :3392

From another machine

nmap -p 3392 -sV <host>
sudo nmap -sU -p 3392 <host>
nc -zv <host> 3392

Block it in the firewall

sudo ufw deny 3392/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 3392" -Direction Inbound -LocalPort 3392 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 3392 used for?

Port 3392 is assigned by IANA to efi-lm (EFI License Management).

Is port 3392 TCP or UDP?

Port 3392 is registered for TCP and UDP.

Is it safe to open port 3392?

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 3392 is open?

On Linux run "ss -ltnup 'sport = :3392'", on macOS "lsof -nP -i :3392", and on Windows "netstat -ano | findstr :3392" to see the local process. From another machine, "nmap -p 3392 <host>" shows whether it is reachable.

05 Related