If you’ve ever dipped your toes into vulnerability management, you’ve probably heard about credentialed and non-credentialed scans. At first, it sounds like a minor detail—do you use a login or not? But the difference between these two approaches has a big impact on what you find and how much value you get from your scanning program.

Let’s break it down in simple terms so you’ll know when to use each, and why both matter if you’re building strong security practices.

What’s a Vulnerability Scan Anyway?

A vulnerability scan is like a routine health check-up for your systems. Specialized tools look for weaknesses—outdated software, missing patches, insecure configurations, or exposed services—that attackers could exploit. These scans don’t fix problems for you, but they highlight what needs attention before it turns into a serious issue.

Now, the twist is how you run the scan: with or without credentials.

Non-Credentialed Scanning

A non-credentialed scan is what most people think of when they first hear about vulnerability scanning. The scanner tests the system from the outside, kind of like a stranger rattling the doorknobs and windows of your house to see what’s unlocked.

Non-credentialed scans are useful because:

  • They show you what an attacker with no insider access might see.

  • They’re quick to set up since you don’t need login credentials.

  • They can highlight misconfigured firewalls, open ports, or exposed services.

The downside? They don’t go very deep. Without logging in, the scanner only gets a surface-level view. It might miss vulnerabilities in software that requires authentication to detect.

Credentialed Scanning

A credentialed scan goes deeper. In this case, you provide the scanner with valid login credentials, so it can see the system from the inside. Instead of just checking doors and windows, it’s like letting a home inspector walk through every room, check the wiring, and peek into the attic.

Credentialed scans are valuable because:

  • They provide much more accurate results.

  • They detect missing patches, weak permissions, and insecure configurations.

  • They reduce false positives since the scanner can directly verify details.

The catch? They require secure handling of credentials and more setup. Plus, you need to make sure those accounts have the right level of access to give the scanner the visibility it needs.

Why Both Approaches Matter

The truth is, neither type of scan is “better” in every situation—they complement each other.

  • Non-credentialed scans simulate how external attackers probe your systems.

  • Credentialed scans reveal the deeper, internal issues that attackers could exploit if they gain access.

Running both gives you a complete picture. Think of it as checking both the outside and the inside of the house before deciding what repairs need to be made.

Why This Matters for CompTIA Certifications

This topic comes up a lot in CompTIA exams, especially CySA+ and Security+.

  • Security+ introduces the basics of vulnerability scanning and the difference between credentialed and non-credentialed approaches.

  • CySA+ goes further, asking you to analyze scan results, prioritize findings, and apply them in a vulnerability management lifecycle.

  • Even CASP+ touches on the enterprise use of scanning, where credentialed scans are critical for compliance and deep assessment.

So, understanding this distinction isn’t just about passing a test—it’s about developing real-world skills. Companies depend on analysts who can explain why they’re running a certain type of scan and what value it brings.

Final Thoughts

At the end of the day, credentialed and non-credentialed scans are two sides of the same coin. One shows you what outsiders see; the other shows you what’s hiding inside. Together, they give you the best shot at finding and fixing vulnerabilities before attackers exploit them.

If you’re preparing for a CompTIA certification, remember this: exams love to test your understanding of how these scans differ. And if you’re working in the field, knowing when to use each will make you a stronger, more trusted security professional.