API Penetration Testing

Identify exploitable vulnerabilities in your application and programming interfaces before attackers do.

Is this for you?

Do you need an API penetration test?

A quick self-check. If several of these sound like you, it is worth a short conversation.

You likely need this if

  • You expose REST, GraphQL or mobile-backend APIs to customers, partners or third parties
  • Your APIs handle authentication, payments, personal data or business-critical logic
  • You are concerned about broken object- or function-level authorization (IDOR, BOLA)
  • A partner, marketplace or integration requires proof your APIs are tested
  • Your last web app test never exercised the API layer directly

Not sure where you land? A short scoping call will tell you plainly, including if you do not need this yet.

Book a scoping call
Service Overview

What is API penetration testing?

A controlled, adversarial security assessment that simulates real-world attacker techniques against your application and programming interfaces - finding the exploitable business-logic and authorization flaws that automated scanners miss.

It is aligned with the OWASP API Security Top 10, then tailored to your protocols (REST, GraphQL, SOAP), authentication flows, data contracts, and regulatory obligations.

Core Outcomes
Identify exploitable API flaws

Find and validate flaws in authentication, authorization, and business logic that automated scanners miss.

Validate security controls

Confirm that implemented controls hold up under realistic, chained attack scenarios.

Quantify business risk

Score findings so stakeholders can prioritize remediation by severity and likelihood of exploitation.

Accelerate remediation

Give developers reproduction steps, affected endpoints, and prioritized fixes that retest quickly.

Technical Necessity

The threat landscape we test for

APIs now carry the data and logic attackers want most. We target the abuse paths that matter, not just the issues a scanner can flag.

Broken Object/Function Level Authorization

Attackers manipulate IDs and endpoints (BOLA/BFLA, IDOR) to reach data and actions outside their permissions.

Business Logic Abuse

Multi-step workflow and rate-limit flaws that scanners cannot understand, leading to fraud or data exposure.

Authentication & Token Weaknesses

OAuth misconfigurations, token replay, and scope-enforcement gaps that enable account and service takeover.

Insecure Third-Party Consumption

Unvalidated upstream APIs and integrations that let an attacker pivot through your supply chain.

Process & Methodology

API testing in practice

Scoping & Recon

Define scope, environment, knowledge level, and rules of engagement, then map endpoints, auth methods, and data contracts.

Assessment & Exploitation

Manual and automated testing of authentication, authorization, input validation, and business logic across endpoints.

Business Impact Validation

Safely exploit verified weaknesses - BOLA, token replay, injection, workflow abuse - to prove real impact.

Reporting & Remediation

An executive risk narrative plus developer-ready findings with evidence, severity, and prioritized fixes.

Key results

Every finding comes validated, with reproduction steps, remediation guidance, and the compliance documentation boards and regulators expect.

Learn what's best for your company

Service Categories

Testing types

We tailor the access model and knowledge level to your risk profile and objectives.

Remote or onsite access

  • Remote: testing performed over the internet, simulating an external attacker - the most common, cost-effective model.
  • Onsite: testing from within your network, simulating an insider or post-breach attacker against internal APIs.

Zero, partial, or full knowledge

  • Zero (black box): no prior information, simulating an external attacker with no inside knowledge.
  • Partial (gray box): some access and documentation, balancing realism and coverage.
  • Full (white box): full docs, source, and credentials for the deepest coverage.
Business Rationale

Use cases

Account Takeover Prevention

Validate auth, token, and session controls so credential and token abuse cannot hijack accounts.

Authorization & BOLA/IDOR

Test object- and function-level authorization to prove sensitive data cannot be reached out of scope.

Business Logic Abuse

Model real workflows to uncover logic flaws that cause fraud, revenue loss, or data exposure.

Supply Chain Security

Validate third-party API consumption and integrations so attackers cannot pivot through vendors.

Reporting & Metrics

Reporting structure and metrics

Management Report

An executive overview of business risk, compliance alignment, and a prioritized remediation roadmap for board review.

Technical Report

Developer-ready findings with affected endpoints, request/response samples, proof-of-concept payloads, and CVSS severity.

Key Performance Metrics

Verified vulnerabilities by severity, affected endpoints, remediation status, time-to-remediation, and retest pass rate.

Ready to strengthen your API security posture?

Close the authorization, token, and business-logic gaps in your APIs before attackers or auditors find them. Get a tailored scoping proposal in less than 48 hours.

Industry Relevance

Securing the modern API surface

Fintech & Banking

The Problem: Payment, banking, and customer APIs are prime targets for account takeover, transaction manipulation, and BOLA-driven data exposure.

The Outcome: We test authentication, authorization, transaction logic, and token handling to support DORA, PCI-DSS, and audit readiness.

AI & ML Development

The Problem: Model and data APIs expand the attack surface and create new supply-chain and abuse paths.

The Outcome: We validate auth, input validation, and third-party consumption so AI services cannot be abused or pivoted through.

Compliance

Regulatory & compliance deep dive (EU focus)

API penetration testing produces the independent, documented evidence EU regulations expect for interfaces supporting critical functions and personal data.

  • DORA (Art. 24, 26): Annual resilience testing of APIs supporting critical functions, with threat-led penetration testing (TLPT) every three years.

  • NIS2 (Annex I): Penetration testing of critical-function APIs to evidence appropriate and proportionate technical measures.

  • EU Cyber Resilience Act: Security testing for products with digital elements that expose programming interfaces.

  • GDPR (Art. 32): Testing validates encryption, access controls, and breach detection across API endpoints handling personal data.

FAQ

API penetration testing FAQ

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