Pen Testing approaches: A Deep Dive into White Box, Black Box, and Grey Box Testing

Serena Gray
3 min readApr 15, 2024

Penetration testing comes with a broad range of activities that involve covering physical assets, network services, wireless and applications. These could also include web or mobile application testing, internal and external infrastructure testing, API testing, physical security testing and social engineering.

To scale up the efficiency of penetration testing activities there are a few approaches that can be used to optimize the testing process. In this article, you will get to know the various approaches to penetration testing.

What is penetration testing?

It is a testing method wherein vulnerabilities are analyzed, detected and exploited within the security system of a cloud, network, web application or API. This in turn helps in avoiding exploitation or breaches by hackers, mitigating the vulnerabilities that have been found and the impact of a successful attack is properly assessed.

The same techniques and tactics are harnessed by the pen testing method as cybercriminals do so that a simulated cyber attack against an organization can be carried out.

This in turn helps the team in knowing whether the security controls are robust enough and whether different types of threats can be properly withstood or not. A range of attack vectors can be simulated by the pen testing method depending on whether it is conducted internally or externally.

The following are the approaches to pen testing:

1. White box penetration testing: In this testing approach, the tester is provided with all sorts of configuration plans, internal documentation etc. When the testers are provided with this information, they can focus on using their skills to exploit issues, rather than conducting vulnerability scanning and host enumeration. Specific concerns can be targeted by this approach such as new segments of a network or new features in an application.

Advantages of white box penetration testing:

  • It performs syntax checking and is able to discover typographical errors
  • It makes sure that the module’s independent paths have been properly exercised
  • It makes sure that the verification of logical decisions has been done with their true and false value
  • The design errors are identified that may have occurred because of the difference between the actual execution and the logical flow of the program.

2. Black box penetration testing: A minimum amount of information is provided to the tester, such as the company name. This is well-suited for those environments that are mature, where there are existing processes already for remediation and vulnerability identification. An attacker can be simulated by a tester with a limited knowledge of the organization. Time is spent by the tester on learning the environment.

Advantages of black box penetration testing:

  • Contradictions in the system and specifications are verified by the tester
  • There is no specific knowledge of the language required and hence tester need not be a full-fledged expert
  • The user’s perspective is taken into consideration while the test is being conducted.

3. Grey box penetration testing: A little bit more information is provided to the tester in this approach, such as networks or specific hosts that can be targeted. A proper idea is gained as to what a targeted attack might look like, without the tester requiring to spend a considerable amount of time collecting information.

Advantages of grey box penetration testing:

  • Access to source code is not required by the tester and hence it is unbiased and non-intrusive
  • There is a clear difference between a tester and a developer and hence the risk of personal conflict is comparatively less
  • Internal information need not be provided about other operations and the program functions.

Conclusion: If you are looking forward to implementing penetration testing for your specific project, then do get connected with a top-notch acclaimed software testing services company that will provide you with a viable and methodical roadmap in line with your project specific requirements.



Serena Gray

I work as a Senior Testing Specialist at TestingXperts. I am a testing professional accustomed to working in a complex, project-based environment.