API Penetration Testing Services

Fortify your APIs against exploits with rigorous testing that ensures seamless functionality and ironclad security.

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Benefits of API Security Testing

API security testing with Raxis shines a spotlight on those hidden cracks, helping you dodge data breaches, ensure rock solid compliance, and keep everything running like clockwork.

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Identifying and Fixing Vulnerabilities

APIs often expose critical backend systems, making them a high-value target for attackers. Our penetration testing identifies vulnerabilities such as insecure authentication mechanisms, improper input validation, and misconfigured endpoints before they can be exploited.

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Ensuring Compliance with Industry Standards

Many industries require APIs to meet strict security regulations, such as PCI DSS, HIPAA, or GDPR. API penetration testing helps ensure compliance by identifying gaps in security and providing detailed reports that demonstrate adherence to required standards.

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Preventing Financial Losses

A compromised API can lead to significant financial losses through data breaches, service disruptions, or regulatory fines. By identifying vulnerabilities early, penetration testing minimizes the risk of costly incidents and ensures your business operations remain uninterrupted.

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Building Trust and Confidence

Securing your APIs demonstrates a commitment to protecting sensitive data and maintaining system integrity. This reassures customers, partners, and stakeholders that your organization prioritizes security, enhancing your reputation in the marketplace.

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API Types We Test

From legacy SOAP services to modern GraphQL implementations, our penetration testers are professional hackers with deep expertise across all API architectures, protocols, and authentication methods.

REST/RESTful APIs

The most common API architecture. We test JSON and XML endpoints, HTTP method security, authentication mechanisms (OAuth, JWT, API keys), parameter tampering, injection attacks, and proper implementation of REST principles.

GraphQL APIs

Increasingly popular for modern applications. We assess query complexity attacks, introspection vulnerabilities, authorization at the field level, batch query exploitation, and GraphQL-specific injection techniques.

SOAP APIs

Enterprise and legacy systems often rely on SOAP. We test XML-based vulnerabilities, WSDL exposure, WS-Security implementation, XML injection, and integration security.

gRPC APIs

High-performance APIs using Protocol Buffers. We test service definitions, authentication interceptors, message validation, and gRPC-specific attack vectors.

WebSocket APIs

Real-time, bidirectional communication channels. We test connection hijacking, message injection, authentication persistence, and WebSocket-specific vulnerabilities.

Third-Party & Partner APIs

APIs that connect your systems to external partners, vendors, or customers. We test integration security, data exposure, authentication delegation, and trust boundary violations.

Mobile Backend APIs

APIs specifically designed for mobile applications. We test mobile-specific attack vectors, client-side secrets, certificate pinning, and offline functionality security.

Internal/Private APIs

APIs used between your internal systems and microservices. Often assumed to be "safe," these are frequently under-protected. We test authentication, lateral movement risks, and trust assumptions.

Legacy & Custom APIs

Proprietary protocols and aging API implementations. We reverse engineer custom formats, analyze undocumented endpoints, and test security of home-grown solutions.

Database APIs

Direct database APIs like MongoDB, Elasticsearch, and Redis endpoints. We test exposure, authentication, query injection, and data exfiltration risks.

Serverless & Function APIs

APIs built on AWS Lambda, Azure Functions, or Google Cloud Functions. We test function-level security, cold start vulnerabilities, and serverless-specific attack vectors.

Webhook Endpoints

Callback URLs that receive data from external services. Often overlooked, these can expose your systems to SSRF, data injection, and replay attacks.

Enterprise-Grade API Security Testing Services

APIs connect your systems, services, and data — and attackers know it. Raxis API penetration testing combines expert manual testing with powerful AI-augmented tools to uncover authentication flaws, data exposure, and authorization vulnerabilities before they're exploited.

Raxis API penetration testing begins with scoping and reconnaissance, where we map out the full picture of your target API like intrepid explorers charting unknown territory. We identify its core type — be it REST, SOAP, GraphQL, or another variant — while carefully cataloging endpoints and poring over essential documentation such as Swagger specifications, Postman collections, or similar tools. In this vital phase of API security testing, we collect details on the architecture, exposed endpoints, authentication methods, and possible attack surfaces that could invite trouble. We also comb through public sources for hidden gems of risk, including hard coded keys, stray comments in code repositories, or earlier revealed vulnerabilities ripe for exploitation in an API vulnerability assessment.

Picture authentication and authorization as the vigilant bouncers at your API's exclusive club — essential for keeping out uninvited guests while ensuring everyone plays by the rules. In this phase of API security testing, we scrutinize the strength of authentication methods like API keys, OAuth tokens, or multifactor authentication, hunting for flaws such as weak token creation or sloppy session handling that might let intruders slip in unnoticed. We also dive into authorization controls during our API vulnerability assessment, verifying that users stick to their roles and access only what they should. This means probing for sneaky privilege escalation tricks or ways to sidestep checks via path traversal and parameter tampering, all to fortify your API against unauthorized mischief.

Think of input validation as the savvy gatekeeper of your API, warding off pesky injection attacks while preserving pristine data integrity like a digital fortress. In this phase of API security testing, we probe how your API manages user input by launching controlled injection attempts, including SQL or NoSQL injection and command injection, to spotlight any cracks during our API vulnerability assessment. We scrutinize error messages too, making sure they stay tight lipped and avoid spilling sensitive details that might tip off would be attackers. Plus, we dive into exception handling to confirm that quirky inputs or wild scenarios do not trigger crashes or open doors to unauthorized entry.

Here is where the action heats up in our API penetration testing — Raxis mimics crafty real world attack scenarios to exploit spotted vulnerabilities and showcase their possible fallout, turning "what if" into eye opening demos. Our exploitation playbook covers probing broken authentication setups, sneaking past rate limits, pulling sensitive data from overly chatty responses, or linking vulnerabilities in clever chains to amp up the assault during this key API security testing stage. We craft proof of concept exploits that let your dev team replay the glitches effortlessly for fixes, all while keeping your live systems safe and sound in our API vulnerability assessment.

Envision rate limiting as the savvy traffic cop of your API world, fending off abuse and denial of service attacks to keep everything flowing smoothly without a hitch. In this phase of API security testing, we challenge these safeguards by cleverly trying to slip past restrictions with a bag of tricks, like flooding endpoints with request barrages or tweaking headers to push the system to its limits. We double check that throttling rules hold firm across every corner in our API vulnerability assessment, while gauging performance under pressure to ensure your API stays resilient and ready for anything.

Raxis delivers a comprehensive report that spotlights every discovered vulnerability, complete with their risks and real world consequences to paint a vivid picture of potential threats. Each issue comes with a handy proof of concept exploit and straightforward remediation steps customized for your dev team, making fixes feel like a breeze in our API security testing flow. We sort vulnerabilities by severity — think critical, high, or medium — to guide your priorities during this API vulnerability assessment, ensuring the biggest dangers get tackled first. Plus, our experts stick around to offer hands on support throughout remediation, guaranteeing resolutions that seal up gaps without sparking fresh troubles.

Once your team rolls out those clever fixes from our recommendations, the Raxis team swoops back in for retesting to confirm every vulnerability has vanished. This crucial step in API security testing guarantees your APIs align with top notch standards and stand strong against future threats in our ongoing API vulnerability assessment.

API Penetration Testing

Comprehensive Role-Based Testing

This essential layer of API security testing during an API vulnerability assessment not only bolsters defenses but also fosters trust in your systems' reliability.

Cross-Customer Users

Software as a Service (SaaS) customers often require testing to validate that the customers who use the web application are not able to access other customers’ data.

Restricted User

Testing as a user with limited permissions makes it possible for our engineers to attempt operations that should only be accessible to higher level users.

Unauthenticated User

We hunt for flaws in the login process as well as authentication bypass techniques such as SQL injection, cross-site scripting, and session fixation.

Administrative User

Once logged in, Raxis maps out the application, looking for technical vulnerabilities as well as business logic gaps and flaws.

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Raxis Hack Stories

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Our stories are based on real events encountered by Raxis engineers; however, some details have been altered or omitted to protect our customers’ identities.

How a Modified API Request Bypassed Role Controls and Exposed Internal Data

APIs can be tricky for developers to secure because, by design, they are often meant to be open to requests from many angles. From internal company web and mobile applications to external API calls allowing vendors and customers to view and manipulate data, API penetration tests look to discover any unintended opening.

Knowing this, our pentester mapped out the API for a SaaS product and attempted to utilize the API in unintended ways. He discovered a chat feature meant to allow API users with specific rights to initiate an AI chat that queried the endpoint, which replied with relevant answers automatically.

Discovering that limited user roles could only chat with the API about publicly available information and were not meant to have access to internal data, our pentester got to work looking for a way to bypass that rule and access internal data as a limited user. Manipulating the query request using Burp Repeater, he discovered that modifying the transaction type triggered the endpoint to reply with sensitive internal data even when authenticated as a limited user. Using the proof of concept in the Raxis pentest report, our client was able to update that endpoint to remove the bypass and protect sensitive data.

Frequently Asked Questions

API penetration testing focuses specifically on the backend services, authentication mechanisms, data validation, and business logic of your APIs—testing how they handle requests, process data, and enforce authorization. Web application testing examines the user interface, client-side code, and how users interact with your application through a browser. APIs often handle sensitive data and business-critical functions without the visibility of a traditional UI, making them attractive targets for attackers. Most modern applications require both types of testing, and we often recommend testing them together for comprehensive coverage.

Absolutely. In fact, undocumented or "hidden" APIs are often the most vulnerable because they receive less security scrutiny. Our penetration testers use traffic analysis, reverse engineering, and dynamic testing to discover and map undocumented endpoints, parameters, and functionality. We test RESTful APIs, GraphQL, SOAP, gRPC, and custom protocols whether they have documentation or not. If your application communicates with backend services, we can find and test those APIs.

Not when done properly. Our API penetration testing is designed to be safe and non-disruptive. We carefully craft requests to avoid triggering rate limits, causing resource exhaustion, or corrupting data. We work with your team to establish testing windows, implement request throttling, and use test accounts when possible. For particularly sensitive production environments, we can test against staging or development instances. However, we always recommend some production testing since staging environments often have different configurations that miss real-world vulnerabilities.

We comprehensively test all aspects of API security controls. For authentication, we evaluate token generation, session management, password policies, multi-factor authentication implementation, and credential transmission security. For authorization, we test role-based access controls (RBAC), privilege escalation vulnerabilities, insecure direct object references (IDOR), and whether users can access resources or perform actions beyond their permissions. We create multiple test accounts with different privilege levels and systematically attempt to bypass authorization checks, access other users' data, and perform unauthorized operations.

Yes. We can test APIs using your existing authentication mechanisms—whether that's OAuth tokens, JWT, API keys, SAML assertions, or custom authentication schemes. You can provide us with test credentials, or we can work with your team to generate appropriate authentication materials. We'll also test the security of the authentication mechanism itself, looking for issues like weak token generation, insufficient token validation, token leakage, and session management flaws.

The most common API vulnerabilities we discover include broken authentication and authorization (allowing unauthorized access to data or functions), excessive data exposure (APIs returning more information than necessary), lack of rate limiting (enabling brute force and denial of service attacks), injection flaws (SQL, NoSQL, command injection through API parameters), business logic vulnerabilities (flaws in how the API processes transactions or enforces rules), mass assignment (allowing users to modify fields they shouldn't access), and security misconfigurations. We also frequently find issues with API versioning, where older, vulnerable API versions remain accessible alongside newer, more secure versions.

Yes. GraphQL APIs have unique security considerations that require specialized testing approaches. We test for GraphQL-specific vulnerabilities including introspection exposure (revealing your entire API schema), query depth and complexity attacks (resource exhaustion through nested queries), batch query attacks, field suggestions that leak information, and authorization bypass through query manipulation. We also test whether your GraphQL implementation properly validates queries, enforces rate limiting, and restricts access to sensitive fields. Our team has extensive experience with GraphQL security and understands how to exploit its unique attack surface.

Timeline varies based on API complexity, number of endpoints, and testing depth required. A simple API with 10-20 endpoints typically takes 3-5 days. Medium complexity APIs with 50+ endpoints, multiple authentication methods, and complex business logic require 1-2 weeks. Large, enterprise-scale API ecosystems with hundreds of endpoints, microservices architectures, and extensive functionality can take 2-4 weeks or more. We'll provide a detailed timeline estimate during scoping based on your specific API environment. For organizations with continuous deployment, we also offer ongoing API testing through our Raxis Attack PTaaS platform.

At minimum, we need API endpoint URLs, authentication credentials or tokens for test accounts, and ideally API documentation (Swagger/OpenAPI specs, Postman collections, or similar). Additional helpful items include information about expected request/response formats, business logic workflows, user role definitions, and any known limitations or sensitive operations to avoid. However, we can also perform testing with minimal documentation—approaching your API the same way an attacker would—to discover undocumented endpoints and functionality. The less information provided, the more realistic the adversarial simulation, but it may extend the testing timeline.

Pricing depends on several factors: API complexity and number of endpoints, authentication mechanisms and number of user roles to test, business logic complexity, testing depth required (basic security vs. comprehensive), and whether testing is one-time or continuous. Simple API assessments typically start around $8,000-$12,000, while comprehensive testing of complex API ecosystems ranges from $15,000-$40,000+. We also offer API testing as part of our Raxis Attack PTaaS subscription for organizations requiring continuous testing. Contact us for a customized quote based on your specific API environment and security requirements.

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