API Penetration Testing

Unlock the full potential of your API with our comprehensive security testing services

API Penetration Testing (CREST Approved in EMEA)

API Penetration Testing is an essential cybersecurity practice for enhancing the security of Application Programming Interfaces (APIs). At Cyber Legion, we conduct rigorous simulations of cyberattacks on APIs to discover vulnerabilities, ensuring secure communication between software systems and protection against unauthorized access. Our process strengthens API security, safeguarding sensitive data from emerging threats.

As a CREST-approved provider in the EMEA region, Cyber Legion offers unparalleled API penetration testing services. Our expertise helps organizations reinforce their cyber defenses, providing comprehensive support to improve API security. Our services not only identify vulnerabilities but also equip you with the knowledge to enhance your security posture, ensuring robust protection against potential risks.

Opt for Cyber Legion’s expertise to navigate API security complexities with confidence, maintaining digital integrity and trust. Elevate your cybersecurity measures with us and stay ahead in the evolving digital landscape, ensuring your APIs are fortified and trustworthy.

Advantages of API Penetration Testing

Enhanced Security Posture

Fortify your API defenses against cyber threats, ensuring your digital gateways are impenetrable to unauthorized access

Data Protection

Safeguard sensitive information by identifying and rectifying vulnerabilities, preventing potential data breaches and leaks

Compliance Assurance

Stay ahead of regulatory requirements with comprehensive testing that ensures your APIs comply with industry standards and the laws

Trust and Reliability

Build confidence among your users and partners by demonstrating a commitment to securing your digital ecosystems

Proactive Threat Identification

Detect and address security vulnerabilities before they can be exploited by attackers, minimizing the risk of cyber incidents

CREST-Approved Expertise

Leverage Cyber Legion’s CREST-approved services in the EMEA region for top-tier API penetration testing

Operational Continuity

Ensure the smooth operation of your services by preventing disruptions caused by security vulnerabilities, maintaining uptime

Cutting-Edge Security Insights

Gain access to the latest security methodologies, allowing you to stay ahead of evolving cyber threats 

Cost Efficiency

Avoid the financial repercussions of security breaches by investing in preventative measures that identify and resolve issues before they escalate

API Testing based on OWASP Security Framework Methodology

API security testing is vital for defending APIs from diverse threats, combining manual and automated strategies to detect vulnerabilities. Cyber Legion leads in this field, leveraging standards like the OWASP Top 10, OWASP ASVS, and OWASP Testing Guide. Our approach includes a deep dive into the API’s architecture, covering authentication, request methods, and user roles across web-based, RESTful, and mobile APIs.

Recognizing the challenges in microservice API assessments, our methodology is customized to address their specific characteristics effectively. We aim to identify and rectify any vulnerabilities, in both live and staging environments, reducing the risk of security incidents. Cyber Legion is committed to enhancing your API’s security, ensuring the protection of your data and assets.

Most Common API Vulnerabilities

Broken Object Level Authorization

Failure to implement proper access controls, allowing attackers to manipulate object references to gain unauthorized access

Broken User Authentication

Vulnerabilities in authentication mechanisms that enable attackers to impersonate legitimate users

Excessive Data Exposure

This directly correlates with Excessive Data Exposure, where APIs reveal more data than they should

Lack of Resources & Rate Limiting

Similar to the lack of rate limiting, leading to potential abuse and denial-of-service (DoS) attacks

Broken Function Level Authorization

This is in line with Broken Function Level Authorization, where functions aren’t properly secured

Mass Assignment

Directly matches Mass Assignment, a vulnerability arising from accepting JSON or XML input without proper filtering

Security Misconfiguration

This is the same as Security Misconfiguration, highlighting issues with insecure default configurations


Matches Injection Flaws, where untrusted data can execute unintended commands

Improper Assets Management

 This corresponds to Improper Assets Management, referring to issues with managing API versions and deployments

Insufficient Logging & Monitoring

Identical to Insufficient Logging & Monitoring, emphasizing the need for adequate logging to detect and respond to attacks promptly.

Cyber Legion’s API Penetration Testing Checklist

  • Authentication Testing

    Verify the robustness of authentication mechanisms. Ensure that authentication tokens or credentials cannot be bypassed

  • Authorization Testing

    Test for endpoint and function level authorization to ensure users can only access resources appropriate to their role

  • Excessive Data Exposure

    Check for APIs exposing more data than needed. Ensure sensitive data is properly protected and only necessary data is exposed

  • Lack of Resources & Rate Limiting

    Assess whether APIs are protected against excessive requests that could lead to Denial of Service (DoS) or service degradation

  • Broken Function Level Authorization

    Test for function-level permissions to verify that users can perform only the actions allowed by their roles

  • Data Validation and Sanitization

    Check for proper data validation and sanitization to prevent common vulnerabilities like cross-site scripting (XSS) and injection attacks

  • Encryption Testing

    Evaluate the implementation of encryption for data in transit and at rest to ensure it meets current standards

  • Security Misconfiguration

    Review configurations for security settings, headers, and other configurations that protect against attacks

  • Injection

    Injection Test for SQL, NoSQL, Command Injection, etc., by supplying malicious input and checking for improper handling

  • Improper Assets Management

    Audit all API versions in use for vulnerabilities, ensuring only current and secure APIs are exposed

  • Insufficient Logging & Monitoring

    Ensure that logging and monitoring are sufficient to detect and alert on malicious activities in real-time

  • API Gateway Security

    Test the security of API gateways for configurations that prevent attacks and limit access based on policy.

Get Your Product's Security Memo

Boost your product's market trust with Cyber Legion's Security Memo. Validate your cybersecurity commitment with our expert assessment. Contact us to obtain your Security Memo and showcase your dedication to top-tier digital security.

Benefits of Working with Cyber Legion

Our Commitment to Your Security

Cyber Legion is your trusted partner in enhancing and protecting your organization’s digital integrity. With our comprehensive security services, including penetration testing and remediation across applications, mobile apps, APIs, IoT devices, and networks, we’re dedicated to fortifying your defenses against cyber threats

Proactive Defense Across All Fronts

Our Secure Client Portal opens the door to an array of specialized security testing services. By adopting best practices and reputable security frameworks, we minimize operational disruption and provide insightful feedback throughout the testing process. Stay informed and secure with our targeted approach to application, mobile, API, IoT, and network security

Navigating Cybersecurity Challenges Together

At Cyber Legion, we believe in a partnership approach to cybersecurity. Our experienced team is committed to offering expert support and guidance, ensuring your needs are met with precision and professionalism. Whether you require a one-time assessment or ongoing services, we’re here to assist you in navigating the complex landscape of cybersecurity

Securing Your Business Continuity

Trust Cyber Legion to keep you one step ahead of cybersecurity threats. Our clear, comprehensive reporting identifies vulnerabilities and outlines actionable steps for improvement, empowering your organization to achieve and maintain the highest levels of security. Let us be your guide in the ever-evolving world of cybersecurity, safeguarding your organization’s future


APIs play a vital role in many important business processes, and it is essential that they are secure and able to withstand attacks. API security testing involves simulating a hacker’s attack on an API to evaluate its security. A security researcher will use various tactics to try to access sensitive user data or disrupt API functionality, and then provide a report to the company outlining any vulnerabilities found and suggesting solutions. Ensuring the security of APIs is critical, especially when they handle personal information.

Achieve all of your security objectives with the help of Cyber Legion’s comprehensive services. Our platform offers both penetration testing and vulnerability management, all in one convenient location. Stay up-to-date on live events and results through our bug tracking, risk dashboards, and ticketing systems. Experience the ultimate in security with Cyber Legion’s integrated solutions.


API Penetration Testing Service FeaturesSupported
Unlimited Cyber Legion CSaaS Platform access
Black, Grey or White Box Testing
Scheduled Security testing service – Work Request Button whenever you want
CVSS (Common Vulnerability Scoring System) for Severity
Automated Security Testing
OWASP Checklists + TOP 10 + Custom Checklists
Executive and Vulnerability Detailed Report
Manual & Automated Security Testing & Risk Validation
Business Logic & Technical Vulnerability Testing
Detailed Exploitation Evidence
Hacker-Style Offensive Pentest
Adherence to OWASP, SANS, CREST Standards
Verifiable Pentest Certificate
Compliance with SOC2, ISO27001, HIPAA
Collaboration with the Stakeholders
Checks against Baseline Security Requirements

The OWASP Security Knowledge Framework is an open source web application that explains secure coding principles in multiple programming languages. The goal of OWASP-SKF is to help you learn and integrate security by design in your software development and build applications that are secure by design.

API’s have increasingly become a target for hackers and malicious users over the years. Improper security can lead to massive data breaches and loss of user data which can go undetected due to the API being abused in a way that seems normal.

API security testing can provide several benefits, including:

  1. Identifying vulnerabilities: API security testing helps identify any vulnerabilities that could potentially compromise the security of your system.

  2. Improving data security: By testing for security vulnerabilities, you can ensure that sensitive data is protected from unauthorized access.

  3. Meeting compliance requirements: Many industries have strict compliance requirements, and API security testing can help ensure that your system meets these requirements.

  4. Protecting against cyber attacks: API security testing can help prevent cyber attacks by identifying and fixing vulnerabilities that could be exploited by hackers.

  5. Enhancing user trust: By ensuring the security of your system, you can build trust with your users and improve customer satisfaction.


Penetration tests (or pen tests) are attacks on your companies’ software and hardware systems, carried out by ‘ethical hackers’ to expose your system’s vulnerabilities. One example is a web application pen test. Web apps, browsers and plug-ins can house sensitive financial or personal data, so hackers are increasingly putting their efforts towards gaining access to them. The test would examine the endpoint of every web application.

The time that penetration testing takes depends on the size and complexity of your organization’s system structure, as well as the scope of the test itself. For the ‘average’ company, a network penetration test should take around three days. For a merchant processing millions of credit cards a year, for example, a pen test will take over a week, or possibly two.

The penetration testing cost depends on the facts identified during scoping, such as the agreed time, goals, technical resources, approach, and remedial support.

Security Testing Pricing list refence 

CREST Approved Penetration Testing Services

Secure your business with top-tier expert knowledge and advanced Penetration Testing (CREST Approved)

Let's collaborate to build and maintain secure businesses

Cyber Legion convert threats into trust by leveraging Advanced Technology and Expertise in Product Security and Business Continuity. Our approach integrates Secure by Design, comprehensive Security Assurance, Red Teaming, Adversary Emulation and Threat Intelligence, Penetration Testing, and Expert Security Advisory and Consultancy. We ensure compliance with meticulous security assurance and detailed documentation, from design to post-market.

As a CREST-certified Penetration Testing provider in the EMEA region, we are committed to the highest security standards.Cyber Legion - CREST Approved