Gray box testing is an application security testing technique that mixes white box and black box testing. In a white box assessment, the tester has complete internal knowledge of the system being tested (source code, design docs, etc.). A black box assessment is performed without any knowledge of the system’s internals.
Gray box testing splits the difference by providing the evaluator with partial knowledge of the system internals. For example, a gray box tester may not have complete knowledge of an application’s source code but may have partial knowledge of it and/or access to design documentation. This provides more insight than black box testing and less than a white box assessment.
A gray box tester has more information than in a black box testing and less than in a white box test. This is intentional and enables a gray box tester to combine the benefits of both approaches.
Gray box testing can improve upon the efficiency and test coverage of a black box assessment by making full use of the information provided. While a tester does not have full access to the application source code, they have enough knowledge and documentation to understand the core functions of the application. This makes it possible to design test cases that focus on likely functionality and security issues rather than testing blindly.
Gray box assessors have less information than in a white box test, which can improve the efficiency and realism of the test. By reducing the number of inputs to the assessment, time can be focused on active testing rather than processing and reviewing provided code and documentation. Additionally, denying assessors full knowledge of the system helps to avoid biases about how a system is designed to work as opposed to how it actually does.
A gray box assessment is a structured evaluation based on the available knowledge of the system under test. It should follow these steps:
Gray box testing can be performed in a few different ways, including:
Black box, white box, and gray box testing provide the tester with varying levels of knowledge about the internals of the system being tested. At one extreme, white box testing provides complete access to source code and design documentation. At the other, black box testers have no internal knowledge of how the application works.
These varying levels of knowledge and access significantly impact the testing process. Some of the major differences include:
Check Point’s Professional Services portfolio can help to support an organization’s application security efforts. White, gray, and black box security assessments are part of Check Point’s Cybersecurity Resilience/Penetration Testing Services.
Learn more about bolstering your organization’s application security program with Check Point’s professional testing services. Also, feel free to contact us to learn more about how a tailored testing program and help to identify and correct security issues within your organization.