Security Scans vs. Human Review

TL;DR

Automated security tools are fast and find common problems. However, they miss things a person can spot. The best approach is to use both – scans to quickly check everything, then human review for the tricky stuff.

1. Understand the Tools

There are lots of different security tools out there. Here’s a quick breakdown:

• Static Application Security Testing (SAST): Checks your code *before* you run it, looking for vulnerabilities like SQL injection or cross-site scripting.
• Dynamic Application Security Testing (DAST): Tests your running application, simulating attacks to find weaknesses.
• Vulnerability Scanners: Check servers and networks for known problems in software versions.
• Software Composition Analysis (SCA): Identifies open-source components you’re using and any known vulnerabilities within them.

Examples include SonarQube, OWASP ZAP, Nessus, and Snyk.

2. What Automated Tools Do Well

1. Speed: They can scan a lot of code or servers very quickly.
2. Coverage: They check everything consistently – no parts are missed due to human error.
3. Common Vulnerabilities: Excellent at finding well-known issues like outdated software or basic coding flaws.
4. Compliance: Help meet security standards by identifying gaps.

3. The Limits of Automation

Automated tools aren’t perfect. They struggle with:

• Logic Flaws: Problems in how your application *works*, not just the code itself.
• Business Rules: Understanding if a vulnerability is actually exploitable within your specific business context.
• False Positives: Reporting issues that aren’t real problems, wasting time investigating.
• Zero-Day Vulnerabilities: New vulnerabilities that haven’t been added to their databases yet.

4. Why Human Review is Still Needed

Security experts can:

• Understand Context: Determine if a reported issue is actually a risk for *your* application.
• Find Logic Flaws: Manually test how the application behaves in different scenarios.
• Perform Penetration Testing: Simulate real-world attacks to identify weaknesses.
• Review Code: Look for subtle vulnerabilities that automated tools miss.

5. Combining Tools and Humans – A Practical Approach

1. Automated Scans First: Run SAST, DAST, SCA, and vulnerability scans regularly (e.g., daily or weekly).
2. Prioritize Results: Focus on high-severity findings first. Most tools give a risk score.
3. Triage False Positives: Quickly dismiss issues that aren’t real problems.
4. Manual Review of High-Risk Findings: Have security experts investigate the remaining issues carefully.
5. Penetration Testing (Periodically): Get a professional penetration test at least once a year, or more often for critical applications.

For example, you might use SonarQube to scan your Java code and then have a security engineer review the top 10 issues reported.

6. Example Workflow with OWASP ZAP

OWASP ZAP is a free DAST tool. A simple workflow:

1. Run an Active Scan:

   zap-cli active-scan --url https://example.com

2. Review the Report: Look for alerts with high confidence and risk levels.
3. Manual Verification: Test the reported vulnerabilities yourself to confirm they are real.

Remember that ZAP, like all tools, will produce some false positives. Manual review is essential.