REST API Security Testing: Complete Guide | Acunetix

REST API Security Testing: Complete Guide

This article was originally published by LOGON’s partner Acunetix. Click here to view the original article.

According to Akamai, nearly a third of all web attacks target APIs – and API portfolios are growing 50–100% year over year. If your testing still focuses on the front end, you’re missing critical risks.

Key API security risks (OWASP API Security Top 10):

Risk	Description
BOLA	Unauthorized access by manipulating object IDs
Broken Authentication	Weak token handling and session management
Broken Function Level Authorization	Access to privileged actions without proper role checks
Injection	SQL, NoSQL, and command injection via API parameters
Excessive Data Exposure	APIs returning more data than necessary
Security Misconfiguration	Exposed debug endpoints, improper CORS

How to test REST API security:

Discover – Inventory all API endpoints (OpenAPI, Swagger, captured traffic)
Authenticate – Handle tokens, sessions, and multi-step workflows
Analyze – Examine request/response structures
Test – Inject payloads, manipulate IDs, fuzz inputs, test privilege escalation
Validate – Focus on exploitable, high-impact findings

What automated tools do:

Import API definitions (OpenAPI/Swagger)
Consume traffic recordings (Postman, proxies)
Test authenticated endpoints with custom headers
Validate real, exploitable vulnerabilities
Reduce false positives

Remember: 95% of API attacks originate from authenticated sources. Authentication alone isn’t enough – you need deep authorization and logic testing.

Want to test your APIs for real vulnerabilities?

LOGON Software Asia – the trusted Acunetix distributor in Asia – offers:

✅ Free Proof of Concept (POC)
✅ Preferred regional pricing
✅ Priority technical support

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