Penetration Testing vs. Vulnerability Scanning: What’s the Difference?

TL;DR

Here’s your informative and unbiased analysis comparing penetration testing vs vulnerability scanning, two security assessment practices that should be part of your organization’s cybersecurity strategy. Penetration testing, also called pentesting or pen test, is a cybersecurity exercise in which a security testing expert, called a pentester, identifies and verifies real-world vulnerabilities by simulating the actions of a skilled threat actor determined to gain privileged access to an IT system or application.

Vulnerability scanning is an automated process used to identify security weaknesses in systems, applications, and networks. It involves scanning devices, software, and configurations for known vulnerabilities, misconfigurations, and outdated patches. There’s so much to uncover when it comes to understanding the differences, benefits, applications, and even misconceptions of these two security practices, but the NetSPI team is here to help you choose the right approach for your cybersecurity needs. Read on.

Pentesting vs Vulnerability Scanning

Let’s start with the basics: cybersecurity is crucial for protecting data, systems, and networks from increasingly sophisticated threats, making it essential to identify and mitigate vulnerabilities before they can be exploited. Penetration testing simulates real-world attacks to uncover weaknesses in defenses, while vulnerability scanning automates the detection of known vulnerabilities across systems and software. Both tools provide proactive security measures, helping to identify gaps, improve risk management, and ensure compliance. Combining penetration testing with regular vulnerability scanning creates a robust defense strategy, ensuring resilience against evolving cyber threats and safeguarding organizational assets.

Overview of Penetration Testing

Penetration testing, also called pentesting or pen test, is a cybersecurity exercise in which a security testing expert, called a pentester, identifies and verifies real-world vulnerabilities by simulating the actions of a skilled threat actor determined to gain privileged access to an IT system or application. Penetration testing enables IT security teams to demonstrate and improve security in networks, applications, the cloud, hosts, and physical locations. Explore our blog entitled What is Penetration Testing? to learn more.

Benefits of Penetration Testing

The primary benefit of penetration testing is to inform security efforts to proactively harden the environment. Penetration testing reveals an organization’s security weaknesses. Penetration testing rates and prioritizes vulnerabilities by severity of outcome factored against the likelihood of such an attack.

• Deliver Secure Software for Less Money
  Security gaps remediated earlier in the software development life cycle (SDLC) cost less to fix than problems found later. Despite best efforts, security vulnerabilities slip through software testing processes. Unlike secure code review, which identifies code that might be exploitable, the vulnerabilities identified by a penetration test are proven to be exploitable.
• Avoid Breaches
  Discover vulnerabilities and exposures proactively, so you can remediate them and prevent an attack — and avoid the costs of downtime and clean-up resulting from a breach. In addition, you preserve an organization’s positive reputation and protect trusted relationships with business partners, customers, and employees.
• Use Human Intelligence Like Attackers Do
  Only a penetration tester (or a malicious attacker) can chain together seemingly low-risk events to verify which vulnerabilities enable unauthorized control. Threat actors adapt to a given environment, so security testers need to adapt, too. Understanding the potential impact of vulnerability scanner results on a specific application or organization requires human expertise and insight.

Challenges with Penetration Testing

It’s also important to consider the potential challenges associated with pentesting. Penetration testing can be resource-intensive, demanding significant time, hardware, and software for both testing and reporting. Your organization may need to allocate dedicated personnel to coordinate the effort, including security analysts, IT staff, and legal teams, to ensure proper planning and execution. But these people can’t be just anyone. 

Effective pentesting requires highly skilled security experts with deep expertise in various attack vectors, security tools, and exploitation techniques. These experts must have the knowledge to simulate sophisticated attacks and assess risks accurately. Given the complexity of cybersecurity, there’s a shortage of qualified pentesters, making the talent pool limited and expensive to hire. Interested in a career in cybersecurity? Explore our open positions.

The last major challenge revolves around the fact that if not executed carefully, penetration testing can unintentionally cause disruptions, including system outages or data loss. For instance, simulating Denial of Service (DoS) attacks or exploiting vulnerabilities in live systems could affect production environments. Proper planning, including clear communication with stakeholders and thorough risk assessments, is essential to minimize disruptions.

Overview of Vulnerability Scanning

Vulnerability scanning is an automated process used to identify security weaknesses in systems, applications, and networks. It involves scanning devices, software, and configurations for known vulnerabilities, misconfigurations, and outdated patches. These scans typically reference databases of known vulnerabilities (such as CVEs) to detect potential security risks.

Vulnerability scanning is essential for maintaining a proactive security posture, enabling organizations to identify and address vulnerabilities before they can be exploited by attackers. It is commonly used for routine assessments, compliance audits, and risk management, helping organizations stay ahead of emerging threats and maintain system integrity.

Benefits of Vulnerability Scanning

Identifying Critical Vulnerabilities
This security practice helps identify critical weaknesses. By automating the process, it rapidly detects known vulnerabilities, allowing organizations to prioritize the most urgent security risks and reduce the attack surface before exploitation.

Improving Security Posture with Actionable Insights
Vulnerability scanning also provides detailed, actionable reports, offering insight into detected weaknesses and their severity. These insights enable organizations to prioritize remediation efforts based on risk, leading to a stronger security posture. Regular scans help track improvements and continuously refine security measures over time.

Challenges with Vulnerability Scanning

However, vulnerability scanning can face several challenges that can impact its effectiveness. False positives occur when the scanner mistakenly identifies a non-issue as a vulnerability, leading to wasted time and resources. A study by International Data Corporation (IDC) concluded that security staff spend an average of 30 minutes for each actionable alert, and 32 minutes for each false positive, indicating a significant resource drain that could be prevented with human intelligence. Conversely, false negatives happen when legitimate vulnerabilities are missed, creating a false sense of security.

Vulnerability scanners are also limited to known vulnerabilities, so they cannot detect zero-day exploits, which are new, undiscovered threats. Regular updates are essential to keep scanning tools current, as the evolving threat landscape introduces new vulnerabilities and attack methods. Additionally, vulnerability scans can produce overwhelming reports that lack context, making it difficult to prioritize risks. Without proper analysis, your organization may struggle to focus on the most critical vulnerabilities, potentially overlooking high-impact issues in favor of less severe ones.

Which Method Should You Use?

Like we’ve mentioned previously, penetration testing and vulnerability scanning are both key components to a comprehensive security strategy, but they serve different purposes and should be used in different contexts. Here’s how to know which method you should use.

An advantage of vulnerability scanning over penetration testing is that it helps identify known vulnerabilities quickly, typically focusing on issues like outdated software, missing patches, or misconfigurations. This is why vulnerability scanning is ideal for routine, automated assessments. We recommend you use it weekly or monthly to continuously identify known vulnerabilities across your systems and networks. It’s especially useful for ensuring compliance, monitoring large-scale environments, and spotting potential issues before they become major risks.

When it comes to a vulnerability scan versus a penetration test, pentesting goes beyond vulnerability scanning by actively exploiting weaknesses to understand the potential impact of those vulnerabilities in a real-world context.  Since penetration testing can provide more meaningful results, it should be used for deeper, more targeted assessments, typically on an annual, quarterly, or per-project basis. Use it when you want to simulate real-world attacks, understand how a potential attacker might exploit your vulnerabilities, and assess the effectiveness of your existing defenses. It’s also valuable after significant changes in your infrastructure or before major deployments.

Looking to learn more about proactive security testing methods and beyond? Reach out to NetSPI for guidance or request a demo of The NetSPI Platform today.