The correct answer is D, Least privilege. In Linux, sudo temporarily grants elevated/root-level privileges to execute administrative commands. The CEH-aligned principle of least privilege requires that users, services, and processes receive only the minimum permissions needed to perform their authorized tasks. Allowing passwordless sudo for multiple commands weakens this control because a normal user can execute privileged actions without reauthentication, increasing the risk of accidental misuse, insider abuse, credential compromise, or privilege escalation. CEH materials emphasize least privilege as an authorization control and also note that sudo provides temporary root privileges. Zero trust is broader and focuses on continuous verification, defense in depth uses layered controls, and CIA refers to confidentiality, integrity, and availability. The specific misconfiguration here is excessive privilege assignment, so the violated security principle is least privilege. A secure configuration should tightly scope sudo permissions to only required commands and users, require authentication where appropriate, and log privileged actions.

Social engineering attacks primarily exploit human behavior rather than technical vulnerabilities.
The most effective mitigation is educating employees through security awareness and training programs so they can recognize and respond appropriately to phishing, vishing, and other manipulation techniques.

In a session donation attack, the attacker donates their own session ID to the target user. In this attack, the attacker first obtains a valid session ID by logging into a service and later feeds the same session ID to the target user. This session ID links a target user to the attacker's account page without disclosing any information to the victim. When the target user clicks on the link and enters the details (username, password, payment details, etc.) in a form, the entered details are linked to the attacker's account. To initiate this attack, the attacker can send their session ID using techniques such as cross-site cooking, an MITM attack, and session fixation. A session donation attack involves the following steps.

Jamming and scrambling are attacks targeting the physical layer of the OSI model, often affecting wireless communication by generating interference to disrupt signal transmission. To mitigate such attacks, one advanced countermeasure is the use of Cognitive Radios.
According to CEH v13 Official Courseware:
* Cognitive radios are intelligent radio systems capable of sensing the radio frequency (RF) environment and dynamically adjusting their operating parameters (e.g., frequency, modulation) to avoid interference and jamming.
* They enable dynamic spectrum access and help in improving spectrum efficiency and resilience against jamming.
* This approach falls under physical-layer security mechanisms.
Incorrect Options:
* A. gets and strcpy are unsafe functions vulnerable to buffer overflow, not relevant to DoS protection.
* B. Allowing all types of packets increases risk and is not a mitigation.
* D. TCP SYN cookies protect against SYN flood attacks and disabling them weakens security.
Reference - CEH v13 Official Courseware:
Module 10: Denial-of-Service (DoS) Attacks
Section: "Defensive Strategies Against Jamming and DoS Attacks"
Subsection: "Physical Layer Countermeasures"