White Box Penetration Testing: Overview

Editor’s note: In this article, we overview the white box penetration testing method, including its value, methodology, and techniques. If you need assistance in verifying your cyber protection level or reinforcing existing security controls, don’t hesitate to check out ScienceSoft’s penetration testing services.

White box penetration testing: the essence

White box penetration testing, also known as clear box or structural testing, is a type of penetration testing in which a tester is given access to the internal makeup of software or an IT infrastructure in order to simulate a hacker’s actions and find potential vulnerabilities.

Unlike black or gray box penetration testing, white box penetration testing implies sharing complete network and system data with a tester (an ethical hacker), which enables them to go deeper and find hidden security flaws. White box penetration testing is commonly used to examine a system’s core parts, especially by companies that develop their own products, or integrate several applications.

Benefits of white box penetration testing

• The most comprehensive analysis of internal and external vulnerabilities from the internal point of view, which is not available to typical attackers.
• The ability of identifying potential weaknesses in areas that are unreachable for black box testing, for example, an app’s source code, design, and business logic.
• Availability at early development stages when there is still no user interface, which is not relevant in case of other types of penetration testing.
• Easy automation of test cases, which helps reduce the time and costs of penetration testing.

White box penetration testing techniques and criteria

When it comes to software security testing, white box penetration testing implies reviewing source code to detect gaps that can make an application vulnerable to cybersecurity threats. The key aspects to be checked include:

Branch coverage

A branch is one of many execution paths that the code can take after processing a decision statement like an if statement. The branch coverage is tested to check whether all branches in a codebase are exercised by tests and no branch leads to abnormal behavior of the application.

Path coverage

The path is a flow of execution that follows a set of instructions. The path coverage examines all possible paths of the software and ensures each path is traversed at least once. The path coverage is far more powerful than the branch coverage and is useful for testing complex builds.

Statement coverage

The statement coverage evaluates if each and every line of code is executed at least once and helps find unnecessary or missing lines.

Apart from the three abovementioned metrics, white box penetration testing can rely on the following criteria:

• Control flow testing
• Data flow testing
• Decision coverage
• Condition coverage
• Modified condition/decision coverage
• Finite state machine coverage

White box pentesting steps

A sample process of software white box penetration testing may look as follows:

Source code review. The first step involves understanding the inner functionality of a target application. During this step, a test engineer reviews the target software’s source code to lay the foundation for creating targeted test cases that will help uncover security flaws.

Test creation and execution.The test engineer creates test cases and executes them in order to find vulnerabilities in the software’s source code. The application testing can be either manual or automated.

Report generation. Finally, the tester creates a report with all the steps and strategies used and communicates the results of the entire testing process to the customer.

Get value from white box penetration testing

Although white box penetration testing may appear complicated and time-consuming, it is an effective way to identify security flaws that are hard to reveal in an application or an IT infrastructure. If you need assistance in conducting white box testing for your IT environment or apps to check if they’re secure, don’t hesitate to contact ScienceSoft’s security testing team.