Updated On 21 July, 2023

Decode Black Box, Grey Box and White Box in PenTesting


In the realm of cybersecurity, organizations face an ever-evolving landscape of threats that can compromise their sensitive data, disrupt their operations, and undermine their trust. To proactively safeguard against these risks, penetration testing, or pentesting, has emerged as a crucial practice.

Penetration testing, otherwise known as pentesting or ethical hacking, is a controlled and systematic simulation of real-world cyberattacks on an organization’s computer systems, networks, and applications. The objective of penetration testing is to surface weak points or vulnerabilities within the digital landscape by simulating a cyber-attack before a cyber adversary even gets the chance to exploit said vulnerabilities.

Three main types of pen tests serve different purposes: black box, white box, and gray box. Each type focuses on specific aspects of security as follows:

  1. Black box testing for an attacker’s view to cover a broader scope.
  2. Grey box testing for an insider view with minimal access.
  3. White box testing for a much deeper inside view.

The main difference between each type is in the amount of information being given to the tester by the organization being tested. When choosing one of these penetration tests, variables to consider include scope, budget, time, and more. Once determined, you can ensure your penetration testing vendor has the appropriate expertise to conduct the type of penetration test you need.

Key Assets

Depending upon the security and compliance requirements for the engagement, any one of the three types of pentests can be used to test digital assets, exposed attack surfaces, and IT systems. A black, white, or gray box test can be focused upon any one of the following internet-connected systems within the organization’s asset inventory:

  • Web Applications
  • Mobile Applications
  • APIs
  • Internal Networks
  • External Networks
  • IoT

Black Box Penetration Test

Blackbox penetration tests are the closest thing to simulating a real-life attack on a digital asset, as the ethical hacker is given absolutely no information or credentials to access any part of the asset being tested.

For example, in a black box web app penetration test, a pen tester would attempt to access privileged information or controls within the application as if they were real cybercriminals. If they had any success, the pen tester detects and exploits one or more vulnerabilities within the asset to demonstrate the web application is not secure. This would be especially true since the pen tester was not given any information and was able to hack into the asset effectively.

When organizations develop web applications using a global community of developers and rely on open repositories like GitHub, there’s an inherent risk of introducing vulnerabilities into the application. Black box testing plays a vital role in identifying and mitigating these risks. For example, in the case of the Apache Struts vulnerability and Google Firebase data exposure, both issues were discovered and fixed later after they had the potential to cause severe damage.

Furthermore, conducting a black box test is especially valuable for web applications, as the pentester will be able to provide the most accurate hacker’s point of view in their final report. According to OWASP (Open Web Application Security Project), 94% of web applications tested reported some variation of broken access control, which gives lower-privilege users access to higher-privilege data to which they should have access. This vulnerability is critical for an organization that handles sensitive information, such as health records and financial details. Conducting a black box web app pentest is a smart investment to ensure known vulnerabilities on the OWASP Top 10 are comprehensively tested for and fixed proactively. Such a test will ensure data leaks, authentication failures, failed access controls, and insecure code issues are addressed before a preventable breach occurs in production.

White Box Penetration Test

White box testing helps identify vulnerabilities from an insider’s view. For instance, a white box test could be used to identify unusual behavior associated with an insider threat (e.g., an unethical employee collaborating with a criminal to gain an initial foothold). A white box pen test can help reveal vulnerabilities that could be exploited in that use case, along with potential impacts.

White box pentesting requires a client to share some details, such as asset information, IP addresses, and credentials, with their penetration tester. While white box penetration testing is nowhere near close to a real-world cyber-attack, it is still a cost-effective and time-saving method of conducting a penetration test.

Whether organizations are storing and transferring data in cloud, traditional, or hybrid environments, white box network penetration testing proves invaluable in discovering exploitable vulnerabilities within the network. By examining the network environment with full knowledge of its internal workings, a white box penetration tester can identify and assess vulnerabilities in endpoints such as workstations, servers, and other devices.

While external network penetration tests provide insights into the network’s perimeter from an attacker’s perspective, internal network penetration tests go a step further. In internal white box testing, the pentester has access to detailed information about the internal network structure and configuration. This allows them to comprehensively evaluate the network’s security, looking for potential access points between the external and internal networks that should not exist.

Gray Box Penetration Test

In a gray box penetration test, a limited amount of information is given to the pentesters conducting the pentest. A gray box test strikes a balance between a white box and a black box.

Gray box penetration testing allows for an “inside and out” approach, allowing the pentesters to test every side of an application. In many cases, pentesters are given login credentials to either a network or application to test the access privileges between distinct levels of users within an asset.

For example, a web application in the healthcare industry could involve a login portal for doctors and patients. It would be an extreme breach of patient privacy if one patient accessed confidential data about other patients that should only be available to doctors; this would be a violation of the HIPAA Security Rule and would incur a fine based on the number of patient records breached. Gray box penetration testing is a strong method to reduce these types of known vulnerabilities before a breach like this could happen.

By integrating gray box testing into the development and maintenance of mobile applications and APIs, organizations can proactively fortify their security posture. This ensures that modern-day solutions like mobile applications are not only efficient in serving the needs of employees and customers but also resilient against potential cyber threats, providing a safer and more secure user experience overall.

Secure Your Organization with Our Certified Penetration Testing Experts

In the modern era of digital business and a rapidly evolving digital landscape, traditional penetration testing methods are proving insufficient for organizations seeking scalability and faster decision-making. To address this, businesses are adopting a hybrid approach, combining human-led expertise with AI-enabled technologies for more effective pentesting.

Adopting separate black, grey, and white box testing methodologies can introduce inefficiencies and overwhelm the system during the remediation process. To streamline testing and facilitate more efficient vulnerability remediation, an integrated approach is recommended. This combined approach harnesses human ingenuity alongside automated tools, enabling the identification of exploitable vulnerabilities and business logic that automated tests might overlook. As a result, organizations benefit from a comprehensive assessment, improved scalability, and quicker time to value their cybersecurity efforts.

With a team of certified penetration testing experts, BreachLock’s PTaaS offers the highest level of security validation for your organization. Our certified professionals have the skills and experience necessary to identify and remediate vulnerabilities, ensuring your organization remains secure and compliant. We prioritize your success and our in-house security experts are ready to start testing for you within one business day. Ensure your cyber security testing is being managed by capable, experienced, certified security professionals who integrate with your in-house team to meet your security goals on time, every time.

Schedule a discovery call with one of our certified pentesting experts to learn how BreachLock’s PTaaS can protect your organization.

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