Pentesting vs Vulnerability Scanning: What’s the Difference?


Many people believe that pentesting and vulnerability scanning are the same thing. The issue is that company owners often buy one when they should be investing in the other. I’ll clarify the difference between pen testing and vulnerability scanning.

A vulnerability scan is a comprehensive, automated test for security flaws. The goal of a penetration test is to find and exploit security flaws in your system through a thorough, hands-on analysis.

Let’s get into more detail.

What is Vulnerability Scanning?

Security professionals actively evaluate computer, system, and network vulnerabilities during vulnerability scans, also known as vulnerability assessments. These scans, often automated, provide a high-level overview of potential attack vectors.

Compliance with regulations like PCI DSS, FFIEC, and GLBA needs the use of thorough vulnerability scans that can look for more than 50,000 vulnerabilities.

Manually triggered or automatically scheduled, vulnerability checks can take anything from a few minutes to a few hours to finish.

Scanning for vulnerabilities and then reporting on them is a passive method of vulnerability management. The owner or IT department actively takes responsibility for prioritizing the fixes for the identified vulnerabilities or verifying whether a scan produced a false positive result.

To ensure the identification of the most critical vulnerabilities, organizations should have a PCI Approved Scanning Vendor (ASV) perform vulnerability scans.

Scan results for vulnerabilities

Following the conclusion of a vulnerability scan, the scanner generates a comprehensive report. Typically, such scans produce a comprehensive list of vulnerabilities and resources for learning more about each vulnerability. Some of them even provide explanations on how to resolve the issue.

The report highlights potential vulnerabilities, but it also includes some false positives. When a scan detects a potential danger that does not exist, it is referred to as a false positive. Verifying the authenticity of reported vulnerabilities to avoid wasting time on false positives is a time-consuming but necessary task. Fortunately, a high-quality scanner will categorize vulnerabilities into risk levels (typically high, medium, or low) and will frequently assign a “score” to a vulnerability, allowing you to focus your investigation efforts on the areas that pose the greatest threat first.

What is Penetration Testing?

A penetration test mimics a hacker’s attempt to break into a system by systematically researching and exploiting weak points. True analysts, also known as ethical hackers, look for security flaws and demonstrate their exploitability.

Hackers use techniques like password cracking, buffer overflow, and SQL injection to attempt network infiltration and data collection without causing damage.

When it comes to locating and fixing security flaws in programs and networks, nothing beats a thorough penetration test. The advantages of a penetration test can be better understood with the help of a medical analogy. An X-ray can help determine what’s wrong with your body when something is wrong internally. A simple X-ray machine can give an image that is clear enough to spot a break in the bone structure but is too blurry to be useful for assessing soft tissue damage. Getting an MRI that creates a detailed 3D image of bone and soft tissues combined is the best way to gain a complete picture of what might be going on within a body.

A simple vulnerability scan is like a hazy X-ray, while a penetration test is like a comprehensive MRI of the system. Penetration testing is essential for discovering hidden security flaws in your network or application. In addition, doing penetration tests regularly is an excellent method of sustaining security in the face of ongoing system and software updates.

Pentesting vs Vulnerability Scanning

Scans and evaluations look for security flaws in a system. A penetration test aims to find and exploit security holes. While automated scans are possible, conducting a penetration test requires multiple skills.

Regular vulnerability scans are necessary to protect sensitive data. Analysts at Secureworks® IR have observed clients running scans weekly, while others neglect them. SecureWorks advises scanning new hardware before deployment and every three months thereafter. Any equipment modifications should prompt an immediate vulnerability scan, which uncovers outdated protocols, certificates, services, and patching needs.

Organizations should monitor changes in ports and services, maintaining baseline records. Vulnerability scanners like Nessus, GFI LANGuard, Rapid7, Retina, or Qualys assist in identifying unauthorized changes and alerting network defenders.

When you compare change-control records with detected changes, you can reveal whether they were authorized or indicate issues like malware or policy violations.

Penetration testing finds vulnerable procedures, security settings, and loopholes for potential compromises. It uncovers issues like unencrypted password transmission, password reuse, and database breaches. While vulnerability scans are frequent, pentests should be done consistently but less often.

To ensure objectivity and minimize potential bias, experts recommend hiring an external vendor for performing penetration tests instead of relying on in-house personnel. Penetration testing involves utilizing various tools, but ultimately, the success of the test relies on the tester. Ideally, the tester should possess extensive knowledge and experience in IT, specifically within the organization’s field. They should possess the ability to think abstractly, anticipate threat actor behaviors, demonstrate thoroughness, and willingly showcase how and why the organization’s environment could be compromised.

A concise report should present the results of the penetration test. The main body of the report should explain the compromised information and the method employed. Appendices can provide additional precise information. The report’s value to the customer depends on its inclusion of specific attack details, the value of the compromised data, and recommendations for enhancing the company’s security.

When picking between a penetration test and a vulnerability scan, what questions should I ask?
When it comes to improving an organization’s security, vulnerability scans and penetration tests (or “pen tests”) both play an important role.

What are the Things to Think About Before Settling on a Service for Your Company?

  • Is there a mandatory test you need to run to meet guidelines set by authorities?
  • Just what are your intended outcomes? How extensively do you desire to engage in preventing cyber attacks, aside from solely reporting them to upper management?
  • How much money do you have set aside for safety measures? Is it possible to hire an outside group of hackers to try to break into your system?
  • Which strategy, proactivity or reactivity, are you attempting to adopt? While vulnerability scans can be useful in any situation, pen tests are most effective when done proactively to bolster existing protection.
  • Have cybercriminals used a zero-day attack, or has a vendor disclosed such a vulnerability? If that’s the case, a vulnerability scan is a great way to find out if that vulnerability is present in your network without breaking the bank.
  • When did your team last implement new software or hardware into your information technology infrastructure? If that’s the case, there may be significant room for misconfigurations that hackers could exploit. Therefore, it’s advisable to conduct a vulnerability check whenever possible.
  • How sure are you that you can withstand even the most severe cyber attacks thanks to the robustness of your security posture? The best way to check your defenses, verify your ongoing remediation efforts, and identify and repair any vulnerabilities is through a penetration test (or “pen test”).


Together, they promote a more secure network and software environment. Pentesting is an occasional MRI for your network’s security, while vulnerability scans are weekly or monthly X-rays. Though costly, pentests simulate real-world attacks by professionals.