White Box, Gray Box, and Black Box Penetration Testing: Complete Guide

Businesses are now facing the snowballing risk of security breaches — in the US alone, the average total cost of a data breach has been over $9 million this year, according to the latest IBM report. No wonder that the need to address such challenges is increasing in direct proportion. 

One of the most efficient and proven methods to check whether your security system is ready to handle a potential attack is penetration (pen) testing. However, it’s not that easy to choose the most appropriate type of testing for your needs. In particular, pen tests vary depending on the level of access you provide to the specialists running one for you. 

The three main types of penetration testing are white box, gray box, and black box methods. So, which of them will work best for you? Keep reading to find out! With dozens of successful penetration tests completed, Iterasec is here to explain the white box vs. black box vs. gray box differences in plain language and help you choose the most suitable testing approach. Let’s get started!

What Is Black Box Penetration Testing?

When conducting black box penetration testing, a tester assumes the role of a cybercriminal without access to the targeted system. In other words, the specialist knows little to nothing about the architecture, source code, and other sensitive aspects of your app or network. 

When using this approach, the unprivileged attacker strives to find any details that would let them compromise the system. In a nutshell, they look for potential vulnerabilities, trying to identify the most typical ones such as security misconfigurations, privilege escalations, injections etc. 

Black box pen testing is a realistic imitation of a cyberattack, meaning that it highlights the system’s most prominent weaknesses before external hacking.

Benefits of Black Box Penetration Testing

Let’s discuss the most notable advantages of black box penetration testing:

• Relevance to real-world attacks. Black box penetration tests are closer to real-life cyber attacks than other methods. With their help, you can predict how an average hacker would try to compromise your app, network, or system.
• Suitability for various forms of attacks. When conducted by experienced testers, the black box methodology lets you prevent different types of potential cyberattacks, including the ones from the OWASP Top 10, such as security misconfigurations, cross-site scripting (XSS), and injection attacks.

Limitations of Black Box Penetration Testing

Here are several limitations of black box penetration testing:

• Undetected internal network vulnerabilities. Some internal weaknesses can go unnoticed since black box pen testers don’t have information about your system. Given that roughly 60% of breaches occur due to insider threats, a black box test may not be enough for your peace of mind.
• Extended Reconnaissance Phase: Testers spend more time gathering information about the system, which can prolong the testing process and increase costs.

When Do You Need Black Box Pen Testing?

Considering the pros and cons listed above, here’s when it’s a good idea to run a black box penetration test:

• Your goal is to check whether your system, app, or network is resistant to external cyber threats. 
• You are looking for a quick yet efficient way to detect potential vulnerabilities in real-world conditions.
• You want to discover typical weaknesses, such as implementation issues or problematic builds, before launching your product.

What Is White Box Penetration Testing?

White box penetration testing, also known as “clear” and “open” testing, is a method of detecting system vulnerabilities more deeply and from an insider’s perspective. When running a white box pentest, professionals check your entire system, looking for inconsistencies in databases, endpoint security issues, and so on. 

When conducting a white box penetration test, specialists require privileged access to your system, including source code, documentation, architecture, credentials, network maps, and more. Testers run a thorough assessment, which usually takes more time and involves static (examining the code without executing the program) and dynamic (running software to examine the code) analysis for debugging. 

When comparing black box vs. white box penetration testing, the latter method doesn’t realistically imitate attackers’ potential behavior. On the other hand, it’s much more detailed and, as a result, can detect more possible threats.  

Benefits of White Box Penetration Testing

Let’s break down the main advantages of white box pen testing:

• Comprehensive analysis. White box security testing provides a detailed overview of all internal system components. It streamlines identifying and addressing vulnerabilities in your databases, access management strategies, and more.
• Assessment of code quality. When comparing black box pen testing vs. white box, the latter makes it easier to detect problems in your code, as it involves various tools to analyze your software.
• Coverage of numerous areas. White box pen testing focuses on multiple components vulnerable to cyberattacks. Whether you’re dealing with cloud-based, hybrid, or traditional architecture, this methodology is a proven way to spot errors putting sensitive data at risk.

Limitations of White Box Penetration Testing

Let’s discover the most critical downsides of white box pen testing.

• Time and resource requirements. White box testing takes much longer than other methods due to the comprehensive analysis it involves. Besides, such tests are complex as they require deep expertise in many technical areas.
• Less realistic in nature. Since testers know a lot (if not everything) about the system they check. That said, such tests may be useful in detection of highly sophisticated and new attack vectors from the outside perspective.

When to Use White Box Pen Testing?

Here are several of the most typical use cases for white box penetration testing:

• You need to run a broad assessment of your system, network, or app to detect internal vulnerabilities.
• You suspect your system has critical weaknesses related to a security issue in your code, database, integrations, servers, etc.
• Your system processes sensitive or confidential data, and you can’t risk exposing it to a potential breach.

What Is Gray Box Penetration Testing?

In terms of access level, gray box pen testing is somewhere between white box and black box methodologies. It provides specialists with limited information regarding your system, application, or network. The key goal is to test internal and external aspects of your security and detect vulnerabilities on both sides. 

The gray box methodology doesn’t require full access to your databases, servers, and other confidential system or app components. It needs typical data an average user operates, such as login credentials. 

One of the primary purposes of the test is to verify whether access permissions work properly. It also lets you check how much damage partly privileged users (or an attacker who managed to gain their credentials) could cause to your system.

Key Benefits of Gray Box Penetration Testing

The key advantages of gray box pen testing include:

• Focus on problematic areas. Gray box penetration testing focuses on the most vulnerable components of your system. Therefore, testers don’t waste time and effort on the aspects that are less likely to become a target for cybercriminals. 
• Control of access and permissions. Gray box testing is ideal for checking whether an average user, such as an employee or customer, can access only the necessary information. It also shows whether potential inconsistencies may lead to serious security challenges.
• Time and resource efficiency. With gray box testing, the team of professionals doesn’t have to run as detailed an analysis as with a white box approach. This way, you can quickly detect the most critical weaknesses and address them proactively.

Limitations of Gray Box Penetration Testing

The most significant cons of gray box pen testing are as follows:

• Lack of in-depth analysis. Gray box penetration testing is an excellent option if you’re looking for flaws in a specific area. However, it may be less effective if your goal is to conduct a comprehensive system checkup.
• Less focus on reconnaissance. The gray box method is not as focused on detecting potential external vulnerabilities as the black box pen test. Thus, it‘s more suitable when looking for the danger from a user with some basic knowledge about your system.

When to Use Gray Box Pen Testing?

Gray box pen testing is your go-to choice if one (or several) of the following statements is true:

• You need a balanced approach when verifying your system at both user and developer levels.
• Your primary goal is to prevent potential insider threats while also keeping external dangers in mind.
• You should focus on the security of a specific aspect of your app, network, or system rather than checking it entirely.

White Box vs. Black Box vs. Gray Box Pen Testing: The Round-Up

Now, let’s wrap up the specifics of each method — here’s our final comparison of black box, white box, and gray box penetration testing.

So, Which “Box” Fits Your Needs?

Now, you’re familiar with all the main penetration testing methods and their specifics. So, how do you choose the perfect approach for your organization’s needs? 

As you can see, there’s no one-size-fits-all option when it comes to pen testing. The correct choice depends on numerous factors. Let’s look at the most crucial ones:

• The specifics of your system, network, or app. Consider how sensitive the data involved is. High-risk systems usually require a tailored approach. Also, take into account other components from both the developer’s and end-user’s points of view.
• The goal of your upcoming testing. Clearly define the purpose of the planned penetration testing. Product owners, testing specialists, and other stakeholders should be on the same page regarding the expected outcomes of the checkup.
• Potentially vulnerable areas. Determine which components of your software or network need verification. The required testing tools and approaches vary depending on whether you want to see if your system can withstand external attacks or verify code quality.
• Time, scope, and budget. As mentioned, black box, white box, and gray box testing methods aren’t equal regarding the required time, money, and resource investments. Choosing the most appropriate pen testing method will help you avoid unnecessary efforts and expenses.

Feel free to explore penetration testing best practices in our blog.

White Box, Gray Box, and Black Box Pen Testing Comparison: Final Thoughts

Whether you need to verify the security of your entire system or check if some specific areas are well-protected against potential breaches, penetration testing is hard to overestimate. However, choosing the proper pen testing method is just as vital.

Black box pen testing is your best bet if you want to know whether your network or application can withstand a real-life cyberattack. White box testing suits those striving to run a more comprehensive internal inspection. Finally, a gray box pen test is a perfect option if you want to balance thoroughness and efficiency.

Still not sure which pen testing method to choose? Interasec is ready to assist you. Our experienced team of cybersecurity professionals can provide you with tailored recommendations. We also ensure a holistic approach to all penetration methodologies, including black box, white box, and gray box testing.

Drop us a line to learn more about our versatile pen testing services!