Certified: The Security+ Prepcast

Every penetration test takes place in a specific context—a testing environment that defines what the testers know, how much access they have, and how realistic the scenario is. These environments are typically categorized as known, partially known, or unknown. Each one has its strengths and weaknesses, and understanding how they work is key to designing meaningful penetration tests and preparing for questions on the Security Plus exam. In this episode, we explore all three environments, focusing on how each influences planning, execution, and results.
Let’s begin with the known environment. In this scenario, the penetration testers are given full access to documentation and system knowledge before the test begins. They might receive network diagrams, configuration details, user credentials, architectural blueprints, and even interviews with system owners. This approach is also known as a white box test, and it’s the most transparent of all testing environments.
The goal in a known environment is not to simulate a stealthy attack, but to thoroughly analyze the systems from the inside out. This method is often used for validating security controls, testing new applications, or confirming that known vulnerabilities have been properly remediated. Because the testers know exactly what’s in place, they can go straight to high-risk areas and perform deep technical analysis without spending time on discovery.
Let’s walk through a practical example. A software development company is preparing to release a new mobile application that will process payment data. Before going live, the company hires a penetration testing team and provides full access to the application code, backend server configurations, and API documentation. The testers use this information to look for logic flaws, insecure input handling, poor encryption practices, and insecure default settings. Because they aren’t wasting time guessing how the system works, they can focus on in-depth testing and provide highly specific recommendations for hardening the application.
The benefit of known environment testing is depth. It allows organizations to verify assumptions, validate that defenses are configured correctly, and identify risks that may not be obvious from the outside. It’s also ideal for compliance scenarios, where demonstrating due care and testing coverage is more important than simulating an outsider’s perspective.
That said, known environment testing isn’t designed to reveal how an attacker would approach a system without inside information. It lacks the realism of a blind attack and may fail to identify vulnerabilities related to social engineering, user error, or network discovery processes. That’s where partially known and unknown environments come into play.
Let’s now turn to partially known environment testing. In this scenario, also called a gray box test, the testers are provided with some information about the environment but not everything. They might receive a user account, partial network maps, or general descriptions of systems. This setup simulates the perspective of an attacker who has limited but nontrivial knowledge—like an insider threat with basic access, or an external attacker who has gathered intelligence through reconnaissance or social engineering.
Partially known environments strike a balance between realism and efficiency. On one hand, the testers have enough information to focus their efforts and avoid complete blind guessing. On the other hand, they still have to think like an attacker—using limited knowledge to uncover and exploit weaknesses.
Here’s a real-world example. A healthcare organization wants to test its internal network resilience. The testing team is given standard employee credentials but no administrative access and no detailed network map. The testers begin by mapping the environment, discovering systems, and attempting to escalate privileges. They find that once on the network, it’s possible to access sensitive data storage systems without multifactor authentication. This finding leads the organization to implement stronger segmentation and access controls. The partial knowledge helped focus the test while preserving realism.
Partially known environments are ideal for organizations that want to simulate a sophisticated adversary who has already compromised a low-level account or obtained some background information. It’s also useful for internal security teams who want to assess how far an attacker could get if a single point of access is breached.
This method offers a mix of tactical relevance and strategic insight. It shows both technical weaknesses and procedural flaws—such as poor user training or failure to detect lateral movement. It’s especially powerful when used alongside blue team detection tools, giving defenders a chance to test their response to subtle but escalating attacks.
Now let’s explore the unknown environment. In this setup, the testers have no prior knowledge of the systems they’re attacking. No diagrams, no credentials, no context. This is known as a black box test, and it simulates the experience of a real external attacker. The testers must perform reconnaissance, identify targets, probe defenses, and attempt to breach the environment without help.
Unknown environment testing is the most realistic form of penetration testing—but also the most time-consuming. The testers begin with footprinting and open-source intelligence gathering. They scan for vulnerabilities, fingerprint systems, and try to exploit entry points. Because they are working from scratch, the test reflects the full attack chain: discovery, access, escalation, and persistence.
Let’s look at another scenario. A retail organization wants to simulate an external attack against its customer-facing systems. The penetration testing team is given only the public IP range. No internal documentation is provided. Over the course of several days, the testers identify a misconfigured web server with an outdated content management system. They exploit the vulnerability, gain shell access, and pivot into internal systems. The findings reveal both a technical weakness and a gap in external monitoring. The company uses this information to patch systems, tighten firewall rules, and enhance intrusion detection capabilities.
Unknown environment testing is valuable for identifying what real attackers are most likely to discover. It also helps validate the effectiveness of detection and response processes. However, it’s less efficient when the goal is to test every corner of a system—since the testers may not reach deep components without assistance.
Organizations that use unknown testing should be clear about their goals. If the goal is to simulate a breach and test detection, unknown is a great choice. If the goal is to evaluate a specific subsystem or validate controls, a known environment may be better.
Some penetration testing engagements combine all three methods. Known testing is used for technical validation. Partially known testing simulates an insider attack. Unknown testing simulates a blind external breach. This blended model gives a complete view of risk and supports layered defense strategies.
From a Security Plus exam perspective, you may see questions that describe penetration testing scenarios and ask which environment is being used. You’ll need to match the level of tester knowledge to the correct label: known, partially known, or unknown.
Here’s a tip. If the question says the tester was given full documentation, it’s a known environment. If the tester has limited access or a basic user account, it’s partially known. If the tester starts with no information at all, it’s an unknown environment.
To access downloadable test planning templates, rules of engagement examples, and environment comparison charts, visit us at Bare Metal Cyber dot com. And if you want the most complete, exam-focused Security Plus guide available—filled with examples and practice questions—go to Cyber Author dot me and order your copy of Achieve CompTIA Security Plus S Y Zero Dash Seven Zero One Exam Success.