Access Control and Business Logic Testing

Access Control and Business Logic Testing

Insecure direct object references (IDOR) vulnerabilities expose unauthorized data through predictable identifiers. Test all object references including numeric IDs, usernames, and filenames for access control enforcement. Enumerate valid identifiers through patterns, incremental testing, or information disclosures. IDOR vulnerabilities often chain with other findings to escalate privileges or access sensitive data.

Horizontal and vertical privilege escalation through access control flaws provides account takeover opportunities. Test accessing other users' resources with your session, administrative functionality with user sessions, and state-changing operations across privilege levels. Forced browsing to administrative URLs, parameter manipulation to change user contexts, and HTTP method tampering sometimes bypass access controls.

Business logic vulnerabilities require understanding application workflows and identifying flaws in implementation. Race conditions in financial transactions, workflow bypass through direct state manipulation, and negative value testing in numeric fields represent common logic flaws. These vulnerabilities resist automated detection, requiring human creativity and systematic thinking to identify.

API endpoint testing reveals functionality hidden from standard web interfaces. Discover API endpoints through JavaScript analysis, developer documentation, or common patterns (/api/, /v1/, REST conventions). APIs often lack security controls present in web interfaces, exposing sensitive operations or data. Test authentication requirements, access controls, and input validation separately for API endpoints.