WPA2-PSK networks authenticate users using a pre-shared key derived from a passphrase. After capturing the 4-way handshake, CEH teaches that the standard and most effective method to recover the key is to perform an offline dictionary attack, where wordlist entries are hashed and compared against the captured handshake values. Offline cracking avoids detection and is significantly faster than brute-force attempts.

The scenario describes modifying the structure and representation of an injection payload while keeping its logical database behavior intact so it bypasses WAF detection. This aligns with transforming query structure to evade pattern-based inspection, where attackers alter syntax or formatting to avoid signature-based filtering without changing the underlying intent of the request.

KingoRoot.apk is effective because it runs directly on the Android device without requiring a computer connection, leveraging system vulnerabilities to gain elevated privileges.

In CEH v13 Module 04: Enumeration, identifying services based on well-known port numbers is foundational for enumeration and scanning activities.
Port 21/TCP is assigned to the File Transfer Protocol (FTP).
FTP is a standard protocol used to upload, download, and manage files on a remote server.
During enumeration, open FTP ports can be probed for:
Anonymous login
Banner grabbing
Directory traversal vulnerabilities
Option Clarification:
A: BGP: Runs on TCP port 179.
C: NFS: Commonly uses port 2049.
D: RPC: Dynamically uses multiple ports.
Correct answer is B. FTP (port 21).
Reference:
Module 04 - Enumeration Ports and Services
CEH eBook Appendix: Common Port Numbers and Protocols