apiApplication & Software

API Security Testing

APIs Are the Backbone of Your Business. One Broken API Can Expose Everything.

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What Is API Security Testing?

API Security Testing finds vulnerabilities in your REST, GraphQL, and SOAP endpoints — the backbone of your mobile apps, web applications, and microservices architecture.

APIs are the most attacked surface in modern applications because they expose business logic directly. Unlike web applications where the frontend can hide some complexity, APIs lay bare the entire data model, authentication mechanism, and business workflow. A single broken API endpoint can expose more data than every other vulnerability combined.

BOLA (Broken Object Level Authorization) — where an API lets you access someone else's data by changing an ID parameter — is the number one API vulnerability globally. We have found BOLA in Indian banking apps, healthcare portals, e-commerce platforms, and government services.

Why Your Business Needs This

APIs expose your business logic directly. A single broken endpoint can expose more data than a web application vulnerability ever could.

In our experience testing Indian applications, we have found APIs that exposed lakhs of user records through BOLA, allowed unlimited money transfers by bypassing server-side amount validation, enabled complete account takeover through broken authentication, leaked sensitive data including Aadhaar numbers through excessive data exposure, and allowed brute-force OTP attacks due to missing rate limiting.

For Indian fintech and e-commerce companies, API security is particularly critical because your payment flows, user authentication, and transaction processing all run through APIs. A vulnerability in a payment API is not just a security issue — it is a direct path to financial fraud.

What You Get

check_circleComplete API endpoint discovery and mapping — including undocumented endpoints
check_circleBOLA/IDOR vulnerability testing across every data-access endpoint
check_circleAuthentication and token security testing — JWT, OAuth, API keys
check_circleRate limiting and abuse prevention validation
check_circleInput validation testing across all parameters — injection, tampering, overflow
check_circleBusiness logic testing at the API level — transaction manipulation, workflow bypass

Why Choose Verentix

We start by reverse-engineering your API — not relying on documentation. We discover endpoints, understand data models, and create custom test cases for YOUR specific APIs.

For Indian applications, we pay special attention to UPI callback APIs, payment gateway integrations, Aadhaar verification endpoints, and any API handling financial transactions. We understand the specific attack patterns targeting Indian payment infrastructure.

Our API testing methodology goes beyond OWASP API Top 10. We test for GraphQL-specific attacks including introspection, batch queries, and nested query DoS. For REST APIs, we test every HTTP method on every endpoint with every user role — a systematic approach that finds the vulnerabilities automated tools miss.

Our Approach

API Discovery (Day 1-2): Map every endpoint through traffic analysis, reverse engineering, and documentation review. We find the endpoints your team forgot about.

Authentication Testing (Day 2-4): API keys, JWT tokens, OAuth flows, session management, and token handling tested for weaknesses.

Authorization Testing (Day 4-7): Systematic BOLA/IDOR testing across every endpoint with every user role. This is where we find the most critical vulnerabilities.

Business Logic Testing (Day 7-9): Custom test cases for your API workflows — payment processing, user registration, data access patterns, and transaction integrity.

Rate Limiting & Abuse Testing (Day 9-10): Brute force resistance, enumeration prevention, and API abuse scenarios tested.

Reporting & Support (Day 10-14): Complete API security report with remediation guidance. Developer walkthrough session included.

Real Results for Indian Businesses

A UPI payment app had their entire transaction history API vulnerable to BOLA — accessing any user's payment history by incrementing the user ID parameter. This affected 20+ lakh transactions and the full payment history of every user on the platform.

An insurance aggregator had their GraphQL API exposing its entire schema through introspection, including internal admin mutations that allowed creating, modifying, and deleting policies without authentication.

A digital lending platform's loan approval API had no server-side amount validation — an attacker could modify the approved loan amount in the API request, potentially disbursing amounts far exceeding the approved limit. The potential exposure was estimated at ₹1.2 crore per day.

Frequently Asked Questions

What types of APIs do you test?expand_more
We test REST APIs, GraphQL APIs, SOAP web services, gRPC endpoints, and WebSocket connections. Our testing covers all API architectures used in modern Indian applications.
Do you test payment and UPI APIs?expand_more
Yes. Indian payment APIs have unique attack surfaces. We test UPI callback manipulation, payment amount tampering, refund abuse, settlement timing attacks, and webhook security.
What is BOLA and why is it critical?expand_more
BOLA (Broken Object Level Authorization) allows attackers to access other users' data by changing ID parameters in API requests. It is the #1 API vulnerability globally. We have found BOLA in Indian banking apps where one customer could access another's account details.
Do you need API documentation?expand_more
No. We reverse-engineer your API through traffic analysis. However, having documentation (Swagger/OpenAPI) speeds up the process and ensures complete coverage.

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