CREST Practitioner Security Analyst (CPSA) 2025 – 400 Free Practice Questions to Pass the Exam

The correct choice is VNC, which operates on port 5900. VNC, or Virtual Network Computing, is a remote desktop sharing system that allows you to remotely control another computer over a network connection. It leverages the RFB (Remote Frame Buffer) protocol, and by default, it listens on port 5900 for incoming connections.

Understanding the context of VNC and its functionality is important; it enables users to see the graphical desktop of a remote machine as if they were sitting in front of it, facilitating support and administration from any location.

In contrast, Telnet typically operates on port 23 and is used for remote management and command-line interface access. LDAP, or Lightweight Directory Access Protocol, primarily operates on port 389 and is used for accessing and maintaining distributed directory information services. HTTP, or Hypertext Transfer Protocol, generally operates on port 80 and is related to web traffic. Each of these services has its defined ports and purposes, making VNC uniquely identifiable on port 5900.