What Is a Vulnerability Scan?

A vulnerability scan is an automated process that checks your systems, apps, and network for known security weaknesses.

Think of it like a security report card:

• Are your servers missing patches?
• Are your firewalls misconfigured?
• Are there outdated libraries in use?

Scanners use known vulnerability databases (like CVE, NIST NVD, OWASP) to flag issues.

Tools include: Nessus, Qualys, Rapid7, OpenVAS.

Why It’s Useful:

• Continuous visibility
• Prioritized list of known weaknesses
• Helps with compliance (SOC 2, ISO 27001, PCI DSS)

Limitations:

• No context or exploitation attempt
• False positives
• Can’t detect logic flaws, chained attacks, or zero-days

Pen tests are manual + creative. They test things scanners can’t:

• Insecure business logic
• Chained vulnerabilities
• Insider threats
• Privilege escalation
• Credential reuse

Why It’s Valuable:

• Real-world risk validation
• Satisfies deeper compliance (PCI DSS, ISO, SOC 2, NIS2)
• Boosts credibility with clients and insurers

Limitations:

• Snapshot in time
• Expensive
• Requires coordination and scoping

How to Know What You Need (Right Now)

Here’s how SaaS teams should approach this:

Real-World Example

SaaS Startup (EU-based, 40 FTE):

• Needed SOC 2 and ISO 27001
• Had monthly vuln scans via Qualys
• Lacked recent pen test

Result after 6-week engagement:

• Identified 3 critical logic flaws not found by scanners
• Used results in SOC 2 audit and security questionnaire
• Closed $250K ARR deal that required proof of pen test