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

Port 5271: StageSoft CueLink messaging

Port 5271 is assigned by IANA to cuelink (StageSoft CueLink messaging), cuelink-disc (StageSoft CueLink discovery).

5271

How cuelink works

Other services
client:5271cuelinkresponse client:5271cuelinkresponse

The client sends a request to port 5271 and the cuelink service answers.

Transport
TCP · UDP
Exposure risk
not rated depends on the program listening
Encryption
Unknownnot stated by the registry
IANA status
Assigned2 registered services
Range
Registered (1024-49151)
Category
Other services
01 Security

Is port 5271 dangerous?

We have no specific security note for port 5271. 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 5271

ServicePortTransportDescriptionReferenceUpdated
cuelink 5271 TCP StageSoft CueLink messaging - 2010-03-26
cuelink-disc 5271 UDP StageSoft CueLink discovery - 2010-03-26

// source: IANA service name and port number registry

03 Check it

Which program uses port 5271, and is it reachable?

Linux

sudo ss -ltnup 'sport = :5271'      # process listening on 5271
sudo lsof -nP -i :5271

macOS

sudo lsof -nP -i :5271

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 5271 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 5271
netstat -ano | findstr :5271

From another machine

nmap -p 5271 -sV <host>
sudo nmap -sU -p 5271 <host>
nc -zv <host> 5271

Block it in the firewall

sudo ufw deny 5271/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 5271" -Direction Inbound -LocalPort 5271 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 5271 used for?

Port 5271 is assigned by IANA to cuelink (StageSoft CueLink messaging), cuelink-disc (StageSoft CueLink discovery).

Is port 5271 TCP or UDP?

Port 5271 is registered for TCP and UDP.

Is it safe to open port 5271?

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 5271 is open?

On Linux run "ss -ltnup 'sport = :5271'", on macOS "lsof -nP -i :5271", and on Windows "netstat -ano | findstr :5271" to see the local process. From another machine, "nmap -p 5271 <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