What is Vulnerability Scanning?
Vulnerability scanning is the process of identifying and analyzing security flaws in IT systems, networks, APIs and applications before they can be exploited. These weaknesses can include missing patches, misconfigurations, outdated software versions, and exposures that attackers commonly exploit. Vulnerability scanning helps organizations find and fix issues before they can be exploited in a real attack.
Why is vulnerability scanning important?
Vulnerability scanning is a foundational security practice because it helps:
Identify security gaps early, before attackers do
Reduce the attack surface by finding exposed services, insecure configurations, and unpatched software
Meet compliance requirements like PCI DSS, SOC 2, ISO 27001, HIPAA
Prioritize remediation efforts by highlighting the most critical risks
Improve overall security posture, by providing continuous visibility into weaknesses
Without regular scanning, organizations often rely on assumptions about security posture, rather than actual data and insights into the overall health of their security program.
How does vulnerability scanning fit into overall security strategy?
Vulnerability scanning is not a standalone solution, but is instead part of a broader layered approach to security.
Vulnerability scanning works in partnership with the following security efforts:
Patch management to remediate identified issues
Web application firewalls (WAFs) to provide compensating controls when vulnerabilities can’t be fixed immediately
Penetration testing for deeper, manual validation of high-risk findings
Monitoring and incident response to detect exploitation attempts
Secure development practices (DevSecOps) to reduce vulnerabilities before deployment
Think of vulnerability scanning as continuous visibility, while other controls provide prevention, protection, and response to security findings.
What are the different types of vulnerability scanning?
Different scans focus on different parts of your environment:
Network vulnerability scanning
Scans IP ranges and network services
Identifies open ports, exposed services, weak protocols, and missing patches
Application vulnerability scanning
Focuses on web applications and APIs
Detects issues like SQL injection, cross-site scripting (XSS), and insecure authentication
Host-based vulnerability scanning
Scans individual servers, endpoints, or virtual machines
Looks for OS-level vulnerabilities, misconfigurations, and outdated packages
Cloud configuration scanning
Evaluates cloud infrastructure
Finds misconfigurations like overly permissive IAM roles or exposed storage buckets
Authenticated vs. unauthenticated scanning
Unauthenticated scans simulate an external attacker’s view
Authenticated scans use credentials to provide deeper, more accurate results inside systems
How does vulnerability scanning work?
Most vulnerability scanners follow a similar process:
Asset discovery
The scanner identifies systems, applications, or endpoints to evaluate.
Fingerprinting and enumeration
The tool gathers information on software versions, services, and configurations.
Vulnerability detection
The scanner compares findings against known vulnerability databases like OWASP Top 10.
Risk scoring and reporting
Detected issues are categorized and prioritized based on severity and exploitability.
Remediation and validation
Teams fix the issues and re-scan to confirm remediation was successful.
Modern tools often integrate with CI/CD pipelines and ticketing systems to automate this workflow.
What are the different vulnerability scanning tools?
Vulnerability scanning tools vary by focus and environment, including:
Network vulnerability scanners. Used for infrastructure and perimeter assessments.
Web application scanners (DAST). Used to identify application-layer issues.
Static application security testing (SAST) tools. Used to scan source code.
Cloud security posture management (CSPM) tools. Help assess cloud configuration risks.
Container and dependency scanners. Help to scan images, libraries, and third-party components.
Many organizations use a combination of tools to cover infrastructure, applications, APIs, and cloud environments.
What are vulnerability scanning best practices?
To get the most value from vulnerability scanning:
Scan regularly (not just annually or for compliance)
Keep asset inventories up to date so nothing is missed
Use authenticated scans where possible for higher accuracy
Prioritize vulnerabilities based on real risk, not just CVSS scores
Validate findings to reduce false positives
Integrate scanning into CI/CD pipelines to catch issues earlier
Pair scanning with compensating controls (like a WAF) when immediate fixes aren’t possible
Track remediation over time to measure improvement and accountability
Vulnerability scanning is most effective when treated as an ongoing process, not a one-time task. When combined with prevention, monitoring, and response controls, it becomes a critical pillar of a modern security program.
How Fastly can help
As discussed above, vulnerability scanning and broader security efforts work hand in hand. Fastly’s Next-Gen WAF can help provide compensating controls when vulnerabilities identified in vulnerability scanning cannot be immediately fixed. The Fastly Next-Gen WAF provides advanced protection for your applications, APIs, and microservices, wherever they live, from a single unified solution.