CompTIA PenTest+ Practice Test

Which protocol is commonly disabled on modern systems due to its lack of encryption?

1. SSH

2. RSH

3. Telnet

4. HTTP

The correct answer is: Telnet

The choice of Telnet as the correct answer is appropriate because Telnet is a protocol that has historically been utilized for remote communication and management of systems. However, it is fundamentally insecure due to the lack of encryption for the data transmitted between the client and server. This means that any information, including usernames and passwords, is sent in plain text, making it susceptible to interception by attackers. Modern systems prefer secure alternatives like SSH (Secure Shell) for remote access, as SSH provides encrypted communication, protecting sensitive data from eavesdropping and man-in-the-middle attacks. RSH (Remote Shell) and HTTP (Hypertext Transfer Protocol) also lack encryption; however, they are used in distinctly different contexts and have been largely replaced or supplemented by more secure protocols such as SFTP (Secure File Transfer Protocol) and HTTPS (HTTP Secure). Despite this, Telnet remains the most commonly disabled protocol specifically due to its widespread use in insecure remote management scenarios.