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// Web

Port 777: Multiling HTTP

Port 777 is assigned by IANA to multiling-http (Multiling HTTP).

777

How multiling-http works

Web
browser:777multiling-http browser:777multiling-http

A browser sends an HTTP request to port 777 and the multiling-http server sends the page back.

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
Web
01 Security

Is port 777 dangerous?

We have no specific security note for port 777. Its risk depends on the program actually listening on it. General advice for web services:

  • Serve it over HTTPS only and check the HTTP security headers.
  • Keep admin consoles and development servers off the Internet.
  • Patch the application server and remove default credentials and sample apps.
02 Registry

IANA registry entries for port 777

ServicePortTransportDescriptionReferenceUpdated
multiling-http 777 TCP, UDP Multiling HTTP - -

// source: IANA service name and port number registry

03 Check it

Which program uses port 777, and is it reachable?

Linux

sudo ss -ltnup 'sport = :777'      # process listening on 777
sudo lsof -nP -i :777

macOS

sudo lsof -nP -i :777

Windows (PowerShell)

Get-NetTCPConnection -LocalPort 777 -State Listen | Select LocalAddress, OwningProcess
Get-NetUDPEndpoint -LocalPort 777
netstat -ano | findstr :777

From another machine

nmap -p 777 -sV <host>
sudo nmap -sU -p 777 <host>
nc -zv <host> 777

Block it in the firewall

sudo ufw deny 777/tcp                                         # Linux (ufw)
New-NetFirewallRule -DisplayName "Block 777" -Direction Inbound -LocalPort 777 -Protocol TCP -Action Block  # Windows
04 FAQ
What is port 777 used for?

Port 777 is assigned by IANA to multiling-http (Multiling HTTP).

Is port 777 TCP or UDP?

Port 777 is registered for TCP and UDP.

Is it safe to open port 777?

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. Serve it over HTTPS only and check the HTTP security headers.

How do I check if port 777 is open?

On Linux run "ss -ltnup 'sport = :777'", on macOS "lsof -nP -i :777", and on Windows "netstat -ano | findstr :777" to see the local process. From another machine, "nmap -p 777 <host>" shows whether it is reachable.

05 Related
:443 HTTPS tcp · udp · sctp · low risk :80 HTTP tcp · udp · sctp · moderate risk :8080 HTTP alternate tcp · udp · high risk :8443 HTTPS alternate tcp · udp · moderate risk :3000 Dev servers / Grafana tcp · udp · moderate risk :5000 Flask / Docker registry / UPnP tcp · udp · moderate risk :8000 HTTP alternate (dev) tcp · udp · moderate risk :8888 Jupyter / HTTP alternate tcp · udp · high risk

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