API Penetration Testing Methodology

API Penetration Testing Methodology

At Fortify Solutions, we perform API penetration testing based on OWASP ASVS, the OWASP Testing Guide, and the OWASP API Security Top 10.
Our approach combines manual deep-dive testing with automated scanning, ensuring we detect vulnerabilities that tools alone cannot find.

We focus on security risks across:

• Authentication & Authorization

• Input Validation & Injection

• Access Control

• Cryptographic Security

• Session Management

• Business Logic Flaws

Our 6-Stage Testing Process

1. Reconnaissance & Scope Definition

• Discover all API endpoints (public & hidden).

• Map authentication flows, session handling, and data sensitivity.

• Assess filtering, throttling, and endpoint reachability.

2. Business Logic Mapping

• Build an access control matrix for roles and permissions.

• Identify high-risk operations and sensitive endpoints.

• Analyze workflows for abuse potential or logic flaws.

3. Automated Enumeration & Scanning

• Crawl and enumerate endpoints using API specifications.

• Perform payload fuzzing, schema validation, and misconfiguration checks.

• Identify vulnerabilities via rule-based and context-aware scanning.

4. Authenticated Testing

• Use valid tokens to simulate legitimate user attacks.

• Test session handling, parameter tampering, and hidden functionality.

• Detect race conditions, authentication bypasses, and privilege escalation.

5. Manual Exploitation

• Validate and exploit vulnerabilities in authentication, injection, and access controls.

• Assess business logic abuse, data exposure, and error handling flaws.

• Test forced parameter switching and workflow manipulations.

6. Reporting & Retesting

• Deliver a prioritized risk report with step-by-step remediation guidance.

• Support remediation with your dev and security teams.

• Retest to confirm vulnerabilities are resolved.

Why Our Method Stands Out

• Standards-Based: Aligned with OWASP & CVE references.

• Comprehensive: Covers technical flaws and business logic abuse.

• Collaborative: Real-time feedback during testing.

• Actionable: Clear remediation steps for faster fixes.