Penetration Testing Series (Part 2): Types of Penetration Testing

Penetration Testing Series (Part 2): Types of Penetration Testing

April 10, 2024
Developer at Bramfitt Tech Labs

Carrying on from the first part of the Penetration Testing series, this week we will outline the different types of Pen Testing and what each does.


The three types are:

  • Black Box
  • White Box
  • Grey Box

Black Box Penetration Testing

Black Box penetration testing is akin to a real-world cyberattack where the penetration tester, starts without any prior knowledge of the target system. This approach effectively simulates an external cyber attacker’s actions, who has no insider information but aims to infiltrate an organisation. The penetration tester conducts thorough reconnaissance during the initial phase, collecting any sensitive data necessary for a successful breach. This method enables them to develop an understanding of the network’s architecture purely based on their independent observations and analysis, much like an unprivileged attacker would.

Using the intelligence gathered the penetration tester designs and executes an attack, attempting actions such as privilege escalation and establishing a persistent presence within the network—albeit without causing actual harm. On completing the test, the penetration tester compiles a comprehensive report detailing the findings and subsequently cleans up the testing environment, ensuring no residues of the testing activities remain.

White Box Penetration Testing

In contrast to Black Box testing, White Box penetration testing provides the tester with complete access to all relevant information about the system, including network maps, login credentials, and IP addresses. This exhaustive access facilitates a more focused and efficient testing process, allowing the tester to simulate specific, sophisticated attack vectors and identify multiple exploit pathways quickly. As such, White Box testing is time-efficient and generally less costly, considering the depth of testing and the reduced need for initial reconnaissance.

Grey Box Penetration Testing

Grey Box penetration testing merges elements of both Black Box and White Box testing methodologies. Testers begin with limited but significant information about the system—such as certain credentials or partial system access. This setup mimics an insider attack or an external attacker who has obtained some level of prior knowledge. Grey Box testing aims to uncover what a privileged user might access or compromise within the system.

This method offers an optimal balance by reducing the need for extensive reconnaissance while allowing testers to focus their efforts more strategically on specific system aspects. For businesses, particularly those with limited resources, Grey Box testing maximises efficiency and outcomes by enabling quicker identification of vulnerabilities without the extensive time and financial investment typically associated with Black Box testing.

Comparing Black Box, White Box, and Grey Box

The choice between Black Box, White Box, and Grey Box penetration testing involves trade-offs in coverage, speed, and efficiency:

Black Box Testing:

Offers the quickest initiation since no prior knowledge is required, mirroring an outsider’s unplanned attack. However, this approach may miss some vulnerabilities due to the lack of initial system insight, potentially reducing its thoroughness and effectiveness.

Grey Box Testing:

Provides a balance between speed and coverage. It is faster than White Box testing due to the reduced need for complete system information but typically offers greater depth than Black Box testing because the testers start with some knowledge.

White Box Testing:

Though the slowest, this approach is the most comprehensive. Testers, equipped with extensive system knowledge, can thoroughly explore all possible security flaws. This method ensures a detailed and exhaustive examination but requires more time to plan and execute effectively.

Each testing type serves different purposes and is chosen based on the specific security needs and resources of the organisation. By understanding the strengths and limitations of each, companies can better tailor their penetration testing strategies to their unique security landscapes.

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