thanks for the help

One of the local university's Student records databases was hacked. A graduate student in the computer engineering department decided to show his skills to his friends to impress them. The student successfully enters the system by calling the help desk and pretending to be the new director of the student records department. During the phone call, "I could not remember the password and do not want to call my supervisor. Would please do me a favor and remind me of my password?". The It Help desk person believed him and gave the password without following the University Security policy. Then the student simply logs in to the database and updated the final grade exam of one of his friends who was failing the class. Answer the following questions Question 1: What reason for this successful attack? What was the vulnerability (Flaw or weakness that allows a threat agent to bypass security)? Question 2: Attack surfaces type? Question 3: Who are the threat actors? Question 4: What can be done to defend against this particular attack (So, it will not happen again)