API Penetration Testing
API interfaces are the heart of modern systems—they connect services, applications, servers, and clients. This also means they are one of the primary targets for cyber attackers.
API penetration testing thoroughly examines the security level of the interfaces, communication channels, authentication mechanisms, authorization controls, and the business logic that governs the flow between services.
The test identifies critical security vulnerabilities, misconfigurations, and logical flaws that could allow unauthorized access, account takeover, data leakage, or manipulation of business processes.
Uncover Critical Vulnerabilities with API Penetration Testing
Compromised APIs are a real risk: they can expose sensitive data, enable bypassing security controls, allow account takeovers, or disrupt internal business processes.
API penetration testing is designed to deeply analyze every layer of exposure—from protocol and authentication to business logic and process flows—identifying vulnerabilities before an attacker can exploit them.
At RedEntry we conduct comprehensive testing based on international standards and aligned with the OWASP API Security Top 10, combined with methodologies such as PTES and NIST.
Our approach combines advanced attack and analysis tools with in-depth manual testing to uncover even subtle and complex vulnerabilities that could cause real damage.
Critical vulnerabilities our API penetration testing can uncover:
- Broken Authentication – bypassing authentication mechanisms
- Rate Limiting Failures – lack of protection against automated attacks
- Sensitive Data Exposure – exposure of tokens, passwords, API keys
- Mass Assignment – unauthorized writing/modification of parameters
- Business Logic Flaws – exploiting weaknesses in business processes
- Misconfigured Communication – weak TLS configuration or unencrypted communication
- Server-Side Request Forgery (SSRF)
- Broken Object Level Authorization (BOLA)
- Injection (SQL / NoSQL / Command)
- Broken Function Level Authorization (BFLA)
What do we offer?
At RedEntry we provide a comprehensive approach to API penetration testing covering architecture, entry points, authentication mechanism, and business logic.
Our testing is based on proven methodologies, with tailored adjustments for each client, ensuring every test reflects the organization’s real risks and system characteristics.
Our approach is focused and delivers practical value:
- Eliminates “noise” and highlights only meaningful findings
- Provides concrete, actionable recommendations
- Includes full documentation, screenshots and attack reproduction steps
- Serves as a practical tool for strengthening organizational security
We contractually guarantee that our reports meet the requirements of leading standards such as ISO, SOC 2, GDPR and more.
Chief Information Security Officer (CISO) at CHEQ
“We worked with RedEntry on a large-scale application penetration test, and the team exceeded all our expectations.
Even before the project began, they took the time to understand our needs, analyzed our systems in depth, and presented us with a clear and accurate picture of the risks. The testing was carried out thoroughly, transparently, and precisely—with detailed reports and practical recommendations that could be implemented immediately.
I highly recommend RedEntry to any organization that wants to ensure its security truly meets the highest standards.”
Benefits of
API Penetration Testing
API penetration testing provides your organization not only with a clear picture of its security posture, but also with real business value—through early risk detection, regulatory compliance and continuous improvement of security processes.
Real-Time Vulnerability Detection
In-depth testing of interfaces, permissions, and business logic to uncover critical weaknesses before they can be exploited.
Compliance with Regulations and Standards
Full support for meeting standards such as ISO 27001, SOC 2, PCI DSS, GDPR—reducing exposure to compliance violations.
Prevention of Data Leaks and API Abuse
Simulation of real-world attacks to identify misconfigurations, exposure of sensitive data and to block potential attack paths.
Strengthening User and Customer Trust
Protecting user data, preventing operational failures, and preserving brand reputation through secure and resilient APIs.
Types of API Penetration Testing
We offer three main types of API penetration testing, depending on the level of information provided to the testers and the organization’s objectives. Each type offers a different testing perspective and provides a more comprehensive understanding of the actual security posture.
Black Box Testing
Execution time: up to 14 business days
Grey Box Testing
Most Popular
Execution time: up to 14 business days
White Box Testing
Execution time: up to 18 business days
Tools We Use
Preparation & Scoping
We begin with a kickoff meeting with key stakeholders, review the system architecture, and define the scope and objectives of the test. This phase includes architecture review, risk assessment, scope definition, and collection of keys/test environments or versions.
Mapping & Information Gathering
Technology fingerprinting, identification of entry points, analysis of API flows, and review of parameter and token behavior.
This phase combines automated scanning with manual analysis to build a target list for penetration attempts.
Controlled Penetration Testing
Testing includes authentication bypass, authorization checks, load and rate testing, business logic analysis, code injections, TLS configurations, SSRF, and more.
All actions are documented to enable reproducibility and scenario comparison.
Reporting & Remediation Recommendations
Findings are translated into clear, actionable insights. The report includes risk ratings, technical documentation, screenshots, remediation recommendations at both code and configuration levels, and prioritization based on business impact.
We also support the remediation process and perform a re-test, delivering a final report and certification.
Why Choose RedEntry
Proven experience delivering hundreds of successful penetration tests for organizations worldwide
Senior ethical hackers with backgrounds in elite cyber units
Full transparency throughout every project
Reports that are clear, actionable, and easy to understand for both executives and technical teams
Tailored pentesting services that fit your systems, size, and regulatory needs
Our deliverables are fully compliant with the strictest industry standards and regulations, including SOC 2, ISO 27001, PCI, and more.
Our Experts
RedEntry’s penetration tests are conducted by cybersecurity professionals with extensive operational experience and training from the world’s leading security organizations.
Our team holds the industry’s most prestigious certifications in information security and offensive security, representing the highest standard of technical expertise in the field.