6000

X11 (X Window System)

Critical Risk

TCP — Remote Access

Port Overview

Port Number 6000
Service Name X11 (X Window System)
Transport Protocol TCP
Category Remote Access
Security Risk Critical
Port Range Registered (1024-49151)

What is Port 6000?

Port 6000 is the base port for X11 (X Window System), the display server protocol used in Unix/Linux graphical environments. X11 display :0 uses port 6000, with subsequent displays using 6001, 6002, etc. Exposing X11 ports over a network without strong authentication (xhost) is a severe security risk allowing screen capture and input injection.

TCP Remote Access

Security Considerations

Port 6000 (X11 (X Window System)) is classified as critical risk. This port should not be exposed to the public internet. The service transmits data without encryption, making it vulnerable to eavesdropping, credential theft, and man-in-the-middle attacks.

Recommendation: Block this port at the firewall. Use encrypted alternatives (SSH, SFTP, HTTPS) instead.

Related Ports — Remote Access