In this section, we will explore the different types of penetration testing (pentesting) that security professionals use to assess the security of systems and applications. Understanding these types is crucial for selecting the appropriate method for a given scenario.

Black Box Testing is a type of pentesting where the tester has no prior knowledge of the internal workings of the system. The tester simulates an external attack to identify vulnerabilities that could be exploited by an outsider.

• No prior knowledge: The tester does not have access to internal documentation or source code.
• Simulates real-world attacks: Mimics the approach of an external attacker.
• Focus on external vulnerabilities: Primarily targets externally accessible systems and applications.

A tester is hired to perform a black box test on a company's web application. They start by gathering information from public sources (e.g., website, social media) and then attempt to find and exploit vulnerabilities without any internal knowledge.

Task: Perform a black box test on a sample web application using only publicly available information.

Steps:

1. Information Gathering: Use tools like Google Dorking and WHOIS lookup to gather information about the target.
2. Scanning: Use tools like Nmap to scan for open ports and services.
3. Vulnerability Assessment: Use tools like OWASP ZAP to identify potential vulnerabilities.

Solution:

White Box Testing, also known as Clear Box Testing, involves a comprehensive assessment where the tester has full knowledge of the system, including access to source code, architecture documentation, and internal network details.

• Full access: The tester has complete knowledge of the system.
• In-depth analysis: Allows for a thorough examination of the system's internal workings.
• Focus on internal vulnerabilities: Targets both internal and external vulnerabilities.

A tester is given access to the source code and architecture diagrams of an internal application. They perform a detailed code review and identify potential security flaws.

Task: Perform a white box test on a sample application with access to its source code.

Steps:

1. Code Review: Use static analysis tools like SonarQube to review the source code.
2. Configuration Review: Check configuration files for security misconfigurations.
3. Testing: Use dynamic analysis tools to test the application in a controlled environment.

Solution:

Gray Box Testing is a hybrid approach where the tester has partial knowledge of the system. This method combines elements of both black box and white box testing.

• Partial knowledge: The tester has limited information, such as user credentials or network diagrams.
• Balanced approach: Combines external and internal perspectives.
• Focus on both internal and external vulnerabilities: Allows for a more comprehensive assessment.

A tester is provided with user credentials and a network diagram of a web application. They use this information to identify and exploit vulnerabilities from both an external and internal perspective.

Task: Perform a gray box test on a sample web application with limited access (e.g., user credentials).

Steps:

1. Login and Explore: Use the provided credentials to log in and explore the application.
2. Scanning: Use tools like Burp Suite to scan for vulnerabilities while authenticated.
3. Exploitation: Attempt to exploit identified vulnerabilities.

Solution:

Understanding the different types of pentesting—Black Box, White Box, and Gray Box—is essential for selecting the appropriate method for a given scenario. Each type has its own strengths and weaknesses, and the choice depends on the specific requirements and constraints of the testing engagement. In the next section, we will delve into the phases of pentesting, providing a structured approach to conducting penetration tests.