APIs are the connective tissue of modern enterprise software. They're also the attack surface that most security testing barely scratches. In our experience testing APIs for telecom BSS platforms, fintech systems, and enterprise SaaS products, we consistently find critical vulnerabilities that automated API testing tools miss entirely.
The Fuzzing Problem
Most automated API security testing relies on fuzzing — sending malformed, unexpected, or boundary-value inputs to endpoints and observing the response. Fuzzing is useful for finding input validation failures, but it fundamentally cannot test authorization logic, business-rule enforcement, or multi-step workflow integrity.
What We Test Instead (OWASP API Top 10)
The OWASP API Security Top 10 provides the framework, but implementation requires human judgment.
**Broken Object Level Authorization (BOLA)** — can User A access User B's data by manipulating object IDs? This is the single most common critical API vulnerability we find, and automated tools miss it because they don't understand which objects belong to which users.
**Broken Function Level Authorization (BFLA)** — can a regular user access admin-only API endpoints? We systematically test every endpoint with every role.
**Unrestricted Access to Sensitive Business Flows** — can an attacker abuse legitimate API flows at scale? We test for automated account creation, mass data scraping, and business-logic abuse that bypasses rate limiting.
Telecom & Fintech APIs: Special Considerations
BSS APIs, payment gateway APIs, and mobile wallet APIs carry revenue. A business-logic flaw in these APIs doesn't just expose data — it enables direct financial theft. We test for billing bypass, transaction replay, double-spending race conditions, and charging manipulation specific to these domains.
The Deliverable Difference
Our API security reports don't just list vulnerabilities — they demonstrate exploitability with full proof-of-concept requests and responses, map each finding to the OWASP API Top 10 category, and provide developer-ready remediation guidance specific to your API architecture.