API Penetration Testing Services
Expose critical vulnerabilities in your REST, GraphQL, and SOAP APIs before attackers exploit them. Our OWASP API Top 10 aligned assessments cover BOLA, broken authentication, mass assignment, injection, and rate-limit bypass — with zero false positives.
REST, GraphQL & SOAP — Full API Protocol Coverage
Each API protocol has a distinct attack surface. Our testers hold deep expertise across all three — ensuring nothing is missed.
REST APIs
The dominant API paradigm, and the most frequently attacked. We scrutinise every endpoint, HTTP verb, and data object for authorization and input validation flaws.
- Broken Object Level Authorization (BOLA / IDOR)
- JWT forgery, algorithm confusion & signature bypass
- HTTP verb tampering (GET → PUT → DELETE)
- Hidden & undocumented endpoint enumeration
- Excessive data exposure & sensitive field leakage
- Parameter pollution & mass assignment attacks
GraphQL APIs
GraphQL's flexibility creates a unique attack surface. We assess introspection exposure, batching abuse, and field-level authorization flaws that REST tests miss entirely.
- Introspection abuse & schema enumeration
- Query batching & alias-based brute force
- Query depth & complexity DoS attacks
- Field-level & object-level authorization bypass
- Injection via GraphQL variables & directives
- Subscription endpoint security review
SOAP & Web Services
Legacy SOAP services often carry significant technical debt and unpatched vulnerabilities. We probe WSDL exposure, XML handling, and WS-Security implementations.
- WSDL enumeration & service discovery
- XML External Entity (XXE) injection
- XML injection & SOAP action spoofing
- WS-Security token replay & bypass
- Message integrity & confidentiality review
- WSDL-disclosed operation abuse
Why API Security Testing is Non-Negotiable in 2025
APIs have overtaken web applications as attackers' primary target. They expose the same business logic and data — but with fewer defensive layers. Broken Object Level Authorization (BOLA), mass assignment, and excessive data exposure are consistently the top findings across every API assessment we conduct.
The challenge is that API vulnerabilities are rarely detectable by automated scanners alone. They require a tester who understands your business logic — how the API should behave, and how an attacker would manipulate it to behave differently. That contextual, manual analysis is at the core of every Adayptus API assessment.
BOLA / IDOR
The #1 API vulnerability — unauthorized access to other users' objects
Mass Assignment
Attackers inject extra fields to modify unintended properties
JWT Vulnerabilities
Algorithm confusion, signature bypass, and claim manipulation
Rate Limit Bypass
Enumeration, brute force, and DoS via absent or weak throttling
OWASP API Security Top 10 — Full Coverage
Every Adayptus API assessment is structured around the OWASP API Security Top 10, ensuring systematic coverage of the most critical and prevalent API risks.
Broken Object Level Authorization
Attackers manipulate object IDs in API requests to access unauthorised resources.
Broken Authentication
Weak authentication mechanisms allow attackers to compromise tokens and gain unauthorised access.
Broken Object Property Level Authorization
Excessive data exposure and mass assignment vulnerabilities in object properties.
Unrestricted Resource Consumption
APIs without proper rate limiting are vulnerable to DoS, brute force, and enumeration.
Broken Function Level Authorization
Attackers exploit predictable API endpoints to access admin functions without authorisation.
Unrestricted Access to Sensitive Business Flows
Abuse of legitimate business workflows for unintended purposes such as scalping or fraud.
Server Side Request Forgery (SSRF)
Malicious API requests that cause the server to fetch unintended internal or external resources.
Security Misconfiguration
Permissive CORS, verbose errors, unnecessary HTTP methods, and missing security headers.
Improper Inventory Management
Shadow APIs, deprecated endpoints, and forgotten staging environments expose hidden attack surface.
Unsafe Consumption of APIs
Blindly trusting third-party API data leads to injection attacks and data integrity failures.
5-Phase API Penetration Testing Methodology
From initial endpoint discovery to remediation verification — a systematic, attacker-simulated approach to API security.
API Discovery & Enumeration
We analyse Swagger/OpenAPI specifications, intercept traffic, and use active enumeration techniques to map all endpoints — including hidden, deprecated, and undocumented routes that are frequently forgotten and unprotected.
Authentication & Authorization Review
We test JWT handling (algorithm confusion, signature bypass, claim manipulation), OAuth2 flows, API key entropy, BOLA/IDOR across all object types, and function-level access control to identify privilege escalation paths.
Input Validation & Injection Testing
We probe every parameter for SQL injection, NoSQL injection, XXE, SSRF, command injection, and GraphQL-specific injection. HTTP verb tampering, parameter pollution, and mass assignment vectors are also covered.
Business Logic & Rate Limit Testing
We test rate limiting bypass techniques, workflow abuse, data exfiltration via excessive exposure, and edge-case business logic that can be exploited for financial fraud, account takeover, or data theft.
Reporting & Remediation Support
You receive a dual-layer report: an Executive Summary and a Technical Findings document with CVSS scores, full HTTP request/response PoC evidence, and API-specific remediation guidance tailored to your stack.
Comprehensive API Security Testing Coverage
From authorization logic to injection attacks — every API attack vector, systematically tested.
OWASP API Security Top 10
Comprehensive testing against all ten OWASP API Security Top 10 risks — the industry-accepted benchmark covering the most critical and prevalent API vulnerabilities found in real-world production environments.
Broken Object Level Authorization
BOLA (also known as IDOR) remains the #1 API risk. We test every API endpoint and object relationship to identify cases where object identifiers can be manipulated to access other users' data or resources.
Authentication & Token Security
In-depth review of JWT implementations, OAuth2 authorization flows, API key management, session token entropy, and refresh token handling to identify authentication bypass and session hijacking vulnerabilities.
Injection & Input Validation
Systematic testing for SQL injection, NoSQL injection, XML/XXE injection, SSRF, GraphQL injection, and command injection across all API parameters, headers, and request body fields.
Rate Limiting & DoS Resilience
We test API gateway rate limiting, resource exhaustion attacks, algorithmic complexity DoS via GraphQL queries, and batch endpoint abuse to identify availability vulnerabilities before attackers exploit them.
API Gateway & Configuration Review
Review of API gateway configuration, CORS policies, security headers, TLS/SSL settings, error message verbosity, and access logging to ensure your API infrastructure is hardened against reconnaissance and attack.
What Sets Our API Testing Apart
Our API security practice goes beyond automated scanning — we think like attackers, not auditors.
Multi-Protocol Expertise
We test REST, GraphQL, SOAP, gRPC, and WebSocket APIs — not just HTTP JSON endpoints.
Zero False Positives
Every finding is manually verified with a working proof-of-concept before it appears in your report.
CI/CD & DevSecOps Ready
We integrate with your pipelines and can provide DAST scripting for continuous API security validation.
Remediation Partnership
Our engineers work alongside your team to verify fixes and ensure vulnerabilities are fully closed.
Industry-Leading Tools & Standards We Use
Frequently Asked Questions
Common questions about API penetration testing and our assessment approach
Ready to Secure Your APIs?
APIs are your most exposed attack surface. Don't rely on automated scans — our manual, OWASP-aligned assessments find what scanners miss. Schedule a consultation today and get a precise API security assessment with zero false positives.
Get in Touch
Ready to secure your future? Reach out to us for a consultation.