API Penetration Testing
Modern applications increasingly rely on APIs to deliver dynamic, interconnected services. At Kairos Sec, we specialize in manual, expert-driven API penetration testing that goes far beyond automated tools. Our methodology follows the latest OWASP API Security Top 10, and is tailored to your architecture, use cases, and real-world threats.
1. Scoping & Reconnaissance
We begin by aligning our testing strategy with your API’s design, threat model, and data sensitivity.
- API Specification Review: Analyze OpenAPI/Swagger files, Postman collections, or API docs to understand functionality and expected inputs/outputs.
- Role & Access Matrix: Identify user roles (admin, guest, partner, etc.) and their respective access levels.
- Recon & Enumeration: Identify all endpoints (including hidden or undocumented), supported methods, input types, and authentication schemes.
2. Authentication & Session Management Testing
Authentication is a high-risk area in API security. We test:
- Broken Authentication: Token hijacking, replay, and predictable tokens
- Session Handling Flaws: Token expiration, revocation, refresh logic
- JWT Analysis: Header validation, weak signing algorithms, key disclosure
3. Authorization & Access Control
We rigorously test the integrity of access controls across all endpoints.
- Object-Level Authorization (BOLA): Attempt to access or manipulate data belonging to other users
- Function-Level Authorization: Ensure privilege boundaries are enforced (e.g., non-admins cannot access admin functions)
- Mass Assignment: Test for unintended field-level access via JSON payload manipulation
4. Input Validation & Injection Testing
We validate input handling and simulate real-world exploitation scenarios.
- Injection Attacks: SQLi, NoSQLi, Command Injection, XML External Entity (XXE), SSRF
- Deserialization Attacks: Test for insecure object handling in APIs that accept serialized data
- Improper Content-Type Handling: Bypass filters by switching between JSON, XML, and multipart formats
5. Rate Limiting & Abuse Scenarios
We evaluate whether your API enforces protections against abuse.
- Rate Limiting Bypass: Using multiple tokens, IPs, or header manipulation
- Authentication Brute Force: Username or token guessing with evasion tactics
- Business Logic Flaws: Abuse of sequence, pricing, or workflow logic for unintended outcomes
6. Sensitive Data Exposure
We ensure your APIs do not unintentionally expose sensitive or regulated data.
- Verbose Error Messages: Information leakage from stack traces or debug output
- Insecure Data in Transit: TLS configuration, certificate pinning, mixed content
- Sensitive Data in Responses: Leaked PII, credentials, session tokens, or backend metadata
7. Reporting & Remediation Guidance
You’ll receive a report tailored for both technical and executive stakeholders.
- Executive Summary: Risk context, severity analysis, and business impact
- Detailed Findings: Each vulnerability includes proof of concept, affected endpoints, and clear remediation steps
- OWASP Mapping: All findings are aligned with OWASP API Top 10
- Follow-up Support: Our consultants remain available for post-test discussions, remediation planning, and retesting
Why Kairos Sec?
Developer-Friendly Reports: Actionable, reproducible, and easy to integrate into sprint cycles
Manual-First, Logic-Aware Testing: We find what scanners miss — including BOLA, privilege escalation, and business logic abuse
Zero Outsourcing: Every engagement is performed by senior security engineers
Full Coverage Across Environments: REST, GraphQL, JSON-RPC, and custom protocols