What is Vulnerability Scanning?

What is a Vulnerability Scan?

Vulnerability scanners are computer programs designed to proactively search your systems, networks, and applications for security weaknesses. 

In the hands of malicious threat actors, these weaknesses are open doors that allow them to breach your network, steal sensitive data, or install ransomware. 

By running these vulnerability scanners, you can find and fix those gaps before attackers do.

Get expert-level external vulnerability scanning here.

What is the vulnerability scanning process like?

Vulnerability scans are fully automated and typically non-intrusive. Vulnerability scanners act as a guard for your network, letting you know where vulnerabilities are without disrupting your daily operations.

Once your vulnerability scan completes, you get a comprehensive logged summary of alerts ranked by severity. You can then review this report and prioritize which weaknesses to patch first.

Note: If you are using SecurityMetrics’ ASV vulnerability scans and have an Intrusion Detection System (IDS) or Intrusion Prevention System (IPS) protecting your network, you may need to add our scanner's IP range to a whitelist or exclusion list. Otherwise, your firewall might block the scanner, leading to an incomplete or inaccurate report.

What is a PCI ASV?

If your business accepts credit cards, you are likely familiar with the Payment Card Industry Data Security Standard (PCI DSS). Requirement 11.3.2 specifically calls for quarterly external vulnerability scanning performed by an ASV.

ASV stands for “Approved Scanning Vendor.” These are cybersecurity organizations, like SecurityMetrics, whose scanning solutions have been rigorously tested, vetted, and officially approved by the PCI Security Standards Council. 

Partnering with a certified ASV ensures your scans meet the strict criteria necessary to fulfill PCI compliance requirements, and helps you protect your organization against threat actors, saving you time and money. 

See also: External Vulnerability Scanning FAQs

Internal vs External Vulnerability Scanning?

The PCI DSS requires two independent methods of PCI scanning: internal and external. This is because they scan a network from different perspectives.

An external vulnerability scan looks for vulnerabilities at your network perimeter or website (from the outside looking in), similar to having a home alarm system on the outside of your house. An internal vulnerability scan looks for network vulnerabilities locally (from the inside looking in), similar to having motion detectors inside your house.

Need Internal Vulnerability Scanning you can count on? Get started here.

See also:  Vulnerability Scanning 101 White Paper

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

Penetration testing (pen testing) and vulnerability scanning are frequently confused, which often leads business owners to purchase one when their compliance or security needs actually require the other. 

While both are essential components of a strong cybersecurity strategy, they serve entirely different purposes.

Vulnerability scanning identifies vulnerabilities, while penetration testing demonstrates their actual impact. 

A penetration test will be much more in-depth and expensive. The decision of whether or not to get a penetration test depends on the size of your business, what data you store, and your specific cybersecurity needs.

See also: Pentesting vs. Vulnerability Scanning: What's the Difference?

Vulnerability Scanning: Guarding Your Sensitive Data

A vulnerability scan is an automated test that examines your security to identify where gaps exist. It’s a quick, cost-effective snapshot of your security posture and is great for regular security upkeep. 

Penetration Testing: Anticipating Real Threat Actors

A penetration test is a live, deep-dive examination conducted by a human security expert. In this scenario, the ethical hacker doesn't just check if the door is unlocked—they actively try to pick the lock, bypass the alarm, disable the cameras, and walk out with the "vault."

A pen tester will look at the automated scan results, find a vulnerability, and attempt to exploit it to see how deep they can pivot into your network. This uncovers complex security flaws that automated scanners often miss, such as logic flaws or human error.

Why You Need Both Vulnerability Scanning and Penetration Testing

Most security frameworks and compliance standards (like PCI DSS) actually require both.

• Use Vulnerability Scanning to maintain a constant, baseline defense, catch new bugs quickly, and meet routine compliance requirements.
• Use Penetration Testing after major network changes, or annually, to test your team's real-world incident response and ensure your critical data is truly secure against a determined attacker.

Relying solely on one or the other leaves your business exposed. Vulnerability scanning offers an excellent, cost-effective way to maintain a baseline of security and catch new bugs on a regular (weekly or monthly) basis. Penetration testing provides a deep-dive, real-world assessment (usually done annually) to ensure your overall defenses can withstand a targeted human attack.

When used together, they form a robust defense strategy that satisfies compliance and protects your hard-earned business reputation.

Get started with SecurityMetrics external vulnerability scanning.