What security principle would a sandbox operate under?

A. Implicit deny
B. Least privilege
C. Defense in depth
D. Availability

Answer: B. Least privilege
Explanation:

Sandboxing and Security Principles

• Least Privilege: This is the core principle of a sandbox. It grants a program the absolute minimum set of permissions and resources (CPU, memory, disk access) required to function.  Because the program cannot access the rest of the operating system or the network, it cannot "privilege escalate" to damage the host machine. 

• Isolation (Segmentation): While not listed as an option, sandboxing is a form of isolation.  It creates a virtual boundary. If a suspicious file is opened in a sandbox and turns out to be ransomware, it can only "encrypt" the virtual files inside the box, leaving your actual hard drive safe. 

•  Control and Observation: Sandboxes are often used by security researchers to observe the behavior of malware without risking the production environment.  

Why the other options are incorrect

• A. Implicit Deny: While a sandbox may deny certain actions by default, Implicit Deny is primarily a rule-based access control principle used in firewalls and ACLs (e.g., "deny all traffic that is not specifically allowed").  

• C. Defense in Depth: Sandboxing is a part of a Defense in Depth strategy, but it isn't the principle it "operates under."  Defense in Depth refers to using multiple, layered security controls (like a firewall, plus an IDS, plus a sandbox).

• D. Availability: Sandboxing can actually hinder availability or performance because it requires extra system resources to maintain the isolated environment.  Its goal is Confidentiality and Integrity of the host system. 

The "CISSP Rule of Thumb": If a question mentions restricting an application's environment or preventing a process from "talking" to the rest of the system, the answer is usually Least Privilege or Isolation.