Cybersecurity professionals and decision-makers are well aware of the practice of penetration testing (pentesting). This practice remains a cornerstone of robust cyber defence strategies, often providing businesses with detailed information about vulnerabilities, heightened cyber-risks, and any weak spots in their infrastructure, networks, and systems.
Given the rise in artificial intelligence (AI) and how many threat actors are leveraging it to influence and strengthen their attack methods, it’s only prudent to highlight the importance of combining knowledge with robust pentesting to protect digital assets and data. Learning the crucial nuances and differences between approved penetration testing methodologies is, therefore, crucial.
This article delves into the different frameworks of penetration testing strategies – namely, white, black, and middle-ground grey box pentesting – and examines them through the lens of the notable OWASP framework. This will give you and your DevOps team valuable insights and ideas to enhance your pentesting processes.
Black, Grey, and White Box Pentesting Frameworks
Penetration testing is conducted by professionals accredited by CREST (the Council for Registered Ethical Security Testers), is a simulated ethical hacking engagement designed to identify and address IT infrastructure, network, and application vulnerabilities.
Pentesting exercises will vary in scale and scope depending on the client, with the clear end goal of evaluating a firm’s security posture.
Black Box Penetration Testing
Black box pentesting, also known as closed-box testing, simulates an external attack with zero prior knowledge of the target system or environment. Ethical hackers will approach the target as a real-world malicious actor would, armed only with open-source or publicly available information. Black box testing is arguably the most challenging and realistic type of pentesting engagement.
Key benefits:
- Attacks are more realistic given the limited initial information
- Emulates real-world external threats, thus providing a more comprehensive evaluation
- Focuses on exploitable vulnerabilities from an outsider’s perspective
Despite these perks, black-box pentesting specialists may find it challenging to initially breach the target’s external defences and replicate advanced attack scenarios, given the lack of prior knowledge.
White Box Penetration Testing
At the opposite end of the pentesting spectrum, white box (or open-box) testing provides ethical hackers with complete access to the target IT environment’s inner systems, including source code, architecture, configuration details, APIs, and more. Unlike black box testing, white box tests give pentesters full knowledge and visibility into the target infrastructure.
Key benefits:
- Allows testers to complete more in-depth security assessments with total visibility
- Allows white-box testers to perform static code analysis to scan vulnerabilities without having to run applications in full, thus reducing risk exposure
- Realistically simulate insider threats or highly sophisticated attack scenarios
Despite this, white-box testing experts need to take more time to identify potential vulnerabilities with complete access to IT data and infrastructure. The need for deeper evaluations means that white-box teams need to comprise experts in network architecture and program source code, to accurately identify vulnerabilities.
Grey Box Penetration Testing
Grey box pentesting strikes a balance between black and white box penetration tests. In a grey-box simulation, testers may only have partial or limited knowledge of their cyber risks, target environments, and systems, mimicking scenarios where attackers have gained some information ahead of their attack.
Key benefits:
- The limited internal knowledge makes for more realistic scenarios where a middle ground is reached
- Simulates advanced persistent threats (APTs) which are more sophisticated and unlikely in black- or white-box exercises
The main drawback of grey-box exercises is that they can be too routine, or ‘middle of the road’ compared to the other two methodologies. Striking the right balance is crucial for acquiring insights that could be found more easily in other simulations.
OWASP Guide for Pentesting
The Open Web Application Security Project (OWASP) provides invaluable resources for security testing, including the OWASP Testing Guide.
This framework offers a comprehensive guide to web application vulnerability identification, applicable across all pentesting methodologies. An OWASP penetration test is designed to identify, exploit, and address these vulnerabilities so that risks can be mitigated before an environment is compromised.
An OWASP pentest can help identify key vulnerabilities like those listed in the OWASP Top Ten Web Application Security Risks. These include:
- Broken access control
- Cryptographic failures
- Injection flaws
- Insecure design
- Security misconfigurations
- Vulnerable components
- Authentication failures
- Software and data integrity failures or breaches
- Security logging and monitoring failures
- Server-side request forgery
A chosen penetration testing methodology will influence the extent and scope of the test, as well as the time taken. Scoping such an engagement will require security personnel to collate vital information prior to the assessment, including:
- The type of application and infrastructure
- The number and hierarchy of user roles
- Network size and segmentation
- Whether the test is external or internal facing
- Disclosure of user credentials (which are responsible for most cloud-based cyber-attacks)
- Whether any REST API backend and endpoints are used
Penetration Testing Must Be Adaptive, Not Reactive
As security trends and cyber threats both evolve – one arguably much faster than the other – security specialists must be adaptive when they approach any type of security engagement, including penetration testing.
As AI and its sister technology machine learning (ML) empower malicious actors, decision-makers must consider using innovative automation technology to enhance their capabilities and apply them across their estate. With a managed service and a holistic approach, organisations can improve vulnerability detection and threat containment.
The rise of cloud computing also means that penetration tests have to be conducted on more cloud-native architectures as well as those with a physical foundation. More businesses back off a hybrid of both, however, meaning that elements of grey box testing with specific processes deployed in white and black box engagements will be key. Penetration testing methodologies must evolve to address the unique challenges and configurations found in embedded systems.
Conclusion: Choosing the Right Approach
Moving beyond point-in-time assessments, businesses must consider adopting a continuous testing approach to provide ongoing security validation and reduce risk exposure. This requires ongoing security training and testing. While each pentesting methodology has its strengths, the choice between black, white, or grey box testing depends on various factors, including the organisation’s security maturity, specific objectives, and available resources.
Black box testing excels in providing a realistic view of external threats but may miss internal vulnerabilities. White box testing offers a comprehensive assessment but can be resource-intensive and may not reflect real-world attack scenarios. Grey box testing often provides a balanced approach, suitable for organisations seeking a mix of depth and breadth in their security assessment.
Ultimately, a holistic security strategy should incorporate elements from across the pentesting spectrum. By leveraging the strengths of each methodology, guided by frameworks like OWASP and informed by emerging trends, businesses can build a robust, proactive defence against evolving cyber threats.
As the threat landscape continues to evolve, so too must our approach to penetration testing. By understanding the nuances of black, white, and grey box methodologies, security professionals can craft tailored, effective strategies to safeguard their digital assets in an increasingly complex cyber world.
Phishing Tackle’s training tools and platform can augment your organisation’s security efforts, ensuring employees (regardless of seniority) remain vigilant and well-prepared to identify and respond to potential threats.
