The Importance of a Clearly Defined Pentesting Scope

Published 11/16/2021, 9:00am

In part two of our blog series on pen testing tips, I’d like to discuss the importance of a clearly defined scope. (Part 1 of this series can be found here).

Before we explore the importance of a well-defined pen testing scope, it’s a good idea to quickly cover the reasons why organizations need a solid penetration testing scope.

So, what is penetration testing? And, why is it so important that organizations invest in it to strengthen their security posture? Pen testing is like a security drill for computer systems. But rather than a bank testing its defenses by simulating a heist, organizations simulate cyber attacks with pen testing to see how real hackers may break into their systems.

In penetration testing, “scope” refers to the applications, users, networks, devices, accounts, and other assets that should be tested to achieve the organization’s objectives. Problems occur when the scope is constrained because of time, budget, or incorrectly defined objectives. On the other hand, challenges can also arise from ‘over-scoping,’ which tends to lead to overspending or a disproportionate impact on operations.

To correctly define scope, organizations should work with their penetration testers before starting the process to identify goals (e.g., security maturity, exposures, vulnerabilities, etc.) and purpose (e.g., compliance).

Scope and the Rules of Engagement

All too often, businesses approach the penetration testing process based on broad hypothetical objectives without fully understanding the multitude of reasons why vulnerabilities and other security concerns exist and why certain penetration testing approaches are useful. Of course, everyone wants to know if they’re vulnerable to attack or get frustrated because employees aren’t taking security seriously enough, but these concerns are very general. They don’t actually define the scope of the penetration test sufficiently enough to help the business understand its overall security posture or maximize the benefits of the penetration testing process.

A clearly defined pen test scope also helps create the foundation for defining the “rules of engagement,” that is, which applications, systems, and infrastructure will be tested, what tools will be used, and when the testing will take place. By working together at the start of the penetration testing process, businesses and penetration testing teams can clearly define the scope and rules of engagement to ensure the best possible testing outcomes.

What to Consider When Defining Scope

The purpose of penetration testing is to mimic real-world attacks in order to identify system, network, data, or user vulnerabilities that would enable an attacker to circumvent security. This means that the penetration testers must not only interact with business systems and users but also potentially breach networks. Penetration testing services require examining the defenses and security controls that currently operate to protect the business. It also requires an in-depth look at how different systems, networks, devices, and users interact with each other so the penetration tester can ascertain if a combination of vulnerabilities can result in a breach or how sophisticated an attacker needs to get in order to succeed in compromising a system.

When defining penetration testing scope, the following items should be considered:

• The types of systems to be tested in terms of whether they are on-premise or cloud
• Existing defenses and security controls, including gaps, vulnerabilities, attack responses, and current security postures
• System, network, and device configurations
• System, network, and device tolerance levels during an attack
• Depth and breadth of attack (i.e., sophistication level) in order to compromise systems
• The entire risk landscape and overall environment in which a threat actor may gain access

In the end, the defined scope of the penetration test directly affects the actual impact and success of the security assessment, making the process crucial.