01Introduction
APIs now carry most application traffic, and they expose business logic directly. There is no UI to hide an object ID or a role check behind, which is why authorization flaws in APIs are the most common serious finding in modern pentests.
02What is API security?
API security is the practice of protecting REST, GraphQL and gRPC interfaces from abuse, covering discovery, authentication, authorization, input validation, rate limiting and monitoring.
The OWASP API Security Top 10 is led by broken object level authorization. API security spans DAST and penetration testing for testing, and gateways and WAFs for runtime protection.
03How API security works
A complete API security program has four parts.
- 1.
Inventory
Find every API, including undocumented and deprecated versions. See attack surface management.
- 2.
Specify
Keep OpenAPI or GraphQL schemas current so testing and validation know what is expected.
- 3.
Test
Exercise authentication, authorization between users and tenants, input handling and rate limits.
- 4.
Protect
Enforce schemas, authentication and throttling at the gateway, and log calls for detection.
04Threats and risks
API attacks rarely look like attacks.
BOLA and IDOR
Changing an ID in the path returns another customer's record.
Broken function-level auth
A regular user calls an admin endpoint that the UI simply never showed.
Mass assignment
Sending an extra field such as role or balance that the backend blindly saves.
Shadow APIs
Old versions left running without the controls added to the new one.
05How Parameter helps
Parameter AI Pentesting tests APIs the way attackers probe them.
Spec and code aware
Agents map endpoints from your OpenAPI specs, your code or live traffic, including ones nobody documented.
Authorization first
Agents hold multiple accounts to test object- and function-level access between users and tenants, the focus of our fintech and healthcare work.
Continuous
Tests re-run as endpoints change, instead of once a year.
