API Penetration Testing

API Penetration Testing Services

Expert-led API pentesting for REST, GraphQL, gRPC, and WebSocket interfaces. We test authorization, authentication, business logic, data exposure, and abuse paths, then deliver reproducible evidence and remediation guidance.

Database

What every API pentest includes

Coverage follows the OWASP API Security Top 10 and is adapted to your architecture, roles, and business logic.

  • Manual testing of authorization and BOLA or IDOR
  • Authentication token session and account flow testing
  • REST GraphQL gRPC and WebSocket coverage
  • Reproducible requests responses and exploit evidence
  • Direct access to the researchers on your engagement
  • Developer focused remediation guidance
  • Fix validation when included in scope

What is API penetration testing?

API penetration testing is a controlled assessment of endpoints, authentication, authorization, data handling, and business flows. Blaze tests REST, GraphQL, gRPC, and WebSocket APIs for BOLA/IDOR, broken authentication, data exposure, injection, and business-logic flaws. Unlike automated scanning, researchers test how identities, roles, objects, functions, and rules interact, then manually validate every finding.

MedalBOLA / IDOR

API1 in the OWASP API Security Top 10 (2023)

Medal400+

organizations trust Blaze worldwide

Why Blaze

Why choose Blaze for API penetration testing?

Get architecture-specific coverage, validated findings, and direct access to the experts doing the work.

Key

Authorization across users and roles

Test whether users, tenants, services, and roles can access only the data and actions they are permitted to use.

Code Block

Evidence developers can reproduce

Findings include complete requests and responses, affected endpoints, business impact, and remediation guidance.

Link

Testing adapted to the architecture

REST, GraphQL, gRPC, and WebSocket each receive protocol-specific testing—not one generic checklist.

Compliance

API pentesting for compliance and beyond

Reports can map relevant findings to SOC 2, ISO 27001, and PCI DSS while staying focused on exploitable API risk.

OWASP API Security Top 10

Current API security risk categories.

OWASP ASVS

Application security requirements.

Shield Check

Compliance support

SOC 2, ISO 27001, and PCI DSS mapping when supported by scope.

NIST SP 800-115

Technical security testing guidance.

PTES

Penetration testing methodology.

CWE Top 25

High-impact software weaknesses.

Expert-led

Expert-led API security testing

Named security researchers run the engagement, validate every finding, and stay available throughout testing and remediation.

MedalNamed

expert team for each engagement

Seal CheckDirect

access throughout testing

BugManual

validation of every finding

Rocket LaunchClear

remediation guidance for engineers

Credentials across offensive security and application security

Research-led testing backed by practical API security experience.

API vulnerabilities we test for

Coverage is shaped by your endpoints, roles, authentication, data flows, business logic, and API architecture.

API1

BOLA and IDOR

Broken object-level authorization across users, roles, services, and tenants.

API2

Broken authentication

Weaknesses in tokens, credentials, sessions, and account flows.

API3

Broken object property-level authorization

Unauthorized access to or modification of sensitive fields.

API4

Unrestricted resource consumption

Rate-limit, expensive-request, and resource-exhaustion paths.

API5

Broken function-level authorization

Administrative operations and privilege boundaries.

API6

Unrestricted access to sensitive business flows

Automated or unauthorized abuse of high-value workflows.

API7

Server-side request forgery

Backend requests to unintended internal services or cloud metadata.

API8

Security misconfiguration

CORS, errors, exposed documentation, gateways, and deployment weaknesses.

Pentesting for REST, GraphQL,
gRPC, and WebSocket APIs

Each protocol receives architecture-specific testing based on its documentation, authentication, data model, and message flows.

Code Block

REST APIs

Endpoint enumeration, HTTP-method tampering, parameter pollution, and rate-limit testing.
Database

GraphQL

Introspection, query-depth/batching abuse, and field-level authorization.
Lightning

gRPC

Protobuf/reflection analysis, stream handling, and metadata testing.
Laptop

WebSocket

Connection/session handling, message tampering, cross-origin behavior, and subscription abuse.
The pentest was straightforward and uncomplicated, with good results.

Software company

Related services

Extend coverage across the web applications, mobile apps, and cloud environments connected to your APIs.

Web App

Web application penetration testing

Test the web applications and workflows your APIs support.

Learn More
Phone Device

Mobile application penetration testing

Test the mobile applications that consume your APIs.

Learn More
Cloud

Cloud penetration testing

Test the cloud environment hosting your APIs.

Learn More

Frequently asked questions

Answers about scope, architecture, access, compliance, and remediation.

Pricing depends on endpoint count, protocols, roles, authentication, business flows, and testing depth. Share your architecture for a fixed scope and quote.
Researchers use multiple accounts and privilege levels to test whether one user, tenant, role, or service can access another party’s data or actions.
Yes. Provide representative credentials and any available OpenAPI, Postman, GraphQL, protobuf, or example-message documentation. Exact access is agreed during scoping.
Yes. Testing is adapted to each protocol, including authorization, query abuse, streaming, subscriptions, message handling, and business workflows.
It can provide independent evidence and map relevant findings when the scope supports it. A pentest does not create compliance by itself.
The current average start time is two weeks, subject to scope, access, environment readiness, and researcher availability.
Yes. Testing can begin externally or include credentials, documentation, architecture, and source context. The access model is agreed during scoping.
When retesting is included, researchers replay the relevant requests and update the report with the result.

Ready to test your APIs?

Talk to an expert about your API architecture, roles, data flows, timeline, and required coverage.