Question

question 17

why is telnet considered to be insecure?

a it automatically blocks access to port 23.
b it transmits data in plain text.
c it uses strong encryption for all communications.
d it can only transmit text, not binary files.

Explanation:

Analyze the security characteristics of Telnet

Telnet is a legacy network protocol used to provide a command-line interface for communication with a device. It lacks built-in security mechanisms, meaning all communications—including usernames, passwords, and commands—are transmitted over the network in unencrypted plain text.

Evaluate the given options

• Option A: Telnet typically listens on port 23 rather than blocking it.
• Option B: Telnet transmits all data, including credentials, in plain text, making it highly vulnerable to eavesdropping and packet sniffing. This is the primary reason it is considered insecure.
• Option C: Telnet does not use encryption; SSH (Secure Shell) is used instead for encrypted communications.
• Option D: While Telnet is text-oriented, its lack of security is due to the lack of encryption (plain text transmission), not its inability to transfer binary files.

Answer:

• (A) It automatically blocks access to port 23.
• (B) It transmits data in plain text. (Correct answer)
• (C) It uses strong encryption for all communications.
• (D) It can only transmit text, not binary files.