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// Other services

Port 2003: Brutus Server

Port 2003 is assigned by IANA to brutus (Brutus Server).

2003

How brutus works

Other services
client:2003brutusresponse client:2003brutusresponse

The client sends a request to port 2003 and the brutus 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 2003 dangerous?

We have no specific security note for port 2003. 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 2003

ServicePortTransportDescriptionReferenceUpdated
brutus 2003 TCP, UDP Brutus Server - 2008-02-28

// source: IANA service name and port number registry

03 Check it

Which program uses port 2003, and is it reachable?

Linux

sudo ss -ltnup 'sport = :2003'      # process listening on 2003
sudo lsof -nP -i :2003

macOS

sudo lsof -nP -i :2003

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 2003 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 2003
netstat -ano | findstr :2003

From another machine

nmap -p 2003 -sV <host>
sudo nmap -sU -p 2003 <host>
nc -zv <host> 2003

Block it in the firewall

sudo ufw deny 2003/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 2003" -Direction Inbound -LocalPort 2003 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 2003 used for?

Port 2003 is assigned by IANA to brutus (Brutus Server).

Is port 2003 TCP or UDP?

Port 2003 is registered for TCP and UDP.

Is it safe to open port 2003?

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 2003 is open?

On Linux run "ss -ltnup 'sport = :2003'", on macOS "lsof -nP -i :2003", and on Windows "netstat -ano | findstr :2003" to see the local process. From another machine, "nmap -p 2003 <host>" shows whether it is reachable.

05 Related
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