Test the interfaces your applications trust.
ShabuShabu Security provides authorized API security testing for REST APIs, application backends and connected services, with a focus on authentication, authorization, object access, data exposure and business logic weaknesses.
APIs expose the rules behind the product.
APIs connect users, applications, services and sensitive data. That makes authorization and business logic just as important as traditional technical vulnerabilities.
A secure endpoint must verify not only that a request is valid, but also that the caller is allowed to perform the requested action on the specific object, account or workflow involved.
Understand API roles
Map how users, applications and service identities interact with protected API functionality.
Test object boundaries
Review whether callers can reach data or actions belonging to another user, account or tenant.
Validate business impact
Determine whether a weak API control can become a realistic product-level security problem.
Core areas of an API security assessment.
The exact test scope depends on the API architecture, authentication model, user roles and sensitivity of the data or actions exposed through the interface.
Authentication
Review how API clients establish identity, maintain trusted sessions and access protected functionality.
Object-Level Authorization
Check whether callers can access or manipulate objects outside the account, tenant or resource boundaries intended for them.
Function-Level Authorization
Assess whether privileged API functions remain restricted to the correct roles and service identities.
Data Exposure
Review API responses and data flows for sensitive information that should not be visible to the requesting caller.
Request & Input Handling
Assess how the API processes parameters, structured data, uploaded content and unexpected request states.
Business Logic
Test whether legitimate API functions can be combined or sequenced in ways that create unintended product behavior.
Resource & Usage Controls
Review whether sensitive operations include appropriate controls around repeated, automated or high-volume use.
Integrations
Assess trust relationships between your API, external systems, webhooks and connected application services.
Error & Response Behavior
Check whether API errors, response differences or metadata expose information that weakens intended security boundaries.
Every request crosses a trust boundary.
API security depends on whether identity, permissions, object ownership and data exposure remain correct throughout the complete request lifecycle.
Caller Identity
Who is making the request and what trust level should that identity receive?
Object Ownership
Does the requested object belong to the current user, tenant or permitted security context?
Action Permission
Is the authenticated caller actually allowed to perform this particular operation?
Request Integrity
Does the API accept fields, states or parameter combinations the application did not intend?
Response Exposure
Is the API returning only the information the caller is supposed to receive?
Workflow State
Can the caller skip, repeat or alter an expected product workflow in a security-relevant way?
What should an API penetration test determine?
Manual testing focuses on whether the API enforces the assumptions that the product and its users rely on.
Identity & Authorization
Data & Product Logic
Authentication proves identity. Authorization protects the product.
A valid API credential should not automatically provide access to every object, function or workflow available through an interface.
We review whether permission decisions remain connected to the specific user, role, resource and action being requested, especially in multi-user and multi-tenant applications.
Testing for APIs across different application architectures.
REST APIs
Endpoint authorization, resource access, input handling and data exposure across REST-style interfaces.
SaaS Backends
Account, role and tenant boundaries within multi-user application backend services.
Mobile App APIs
Server-side interfaces used by mobile clients, with emphasis on authorization and sensitive application actions.
Connected Services
APIs used between systems, partners, webhooks and external services where trust crosses application boundaries.
From API mapping to verified remediation.
The assessment is structured around authorized endpoints, user roles, API documentation, application workflows and the security-sensitive functionality exposed by the interface.
Define the scope
Identify API environments, permitted endpoints, credentials, user roles and engagement restrictions.
SCOPE / ENDPOINTS / ROLES
Map API behavior
Understand objects, functions, request flows, authorization decisions and sensitive data paths.
MAP / OBJECTS / TRUST
Test boundaries
Perform controlled manual testing against identity, authorization, data and business logic controls.
TEST / ACCESS / LOGIC
Report & retest
Document validated findings, explain impact and optionally confirm remediation after fixes.
REPORT / FIX / VERIFY
Findings engineers can map back to the interface.
The final assessment is structured around affected API functionality, security impact and the controls required to reduce the identified risk.
Executive Summary
A concise overview of the API security posture and the highest-priority issues identified.
Affected API Areas
Clear identification of the interface, resource or workflow associated with each finding.
Impact Analysis
An explanation of how a weakness may affect data confidentiality, permissions or product behavior.
Technical Evidence
Relevant request and response context needed to understand validated security findings.
Remediation Guidance
Recommendations focused on strengthening authorization, input validation and other affected API controls.
Retesting
Optional verification that previously identified API weaknesses have been successfully addressed.
When an API security assessment creates the most value.
Before API launch
Review security boundaries before exposing a new API to applications, partners or public users.
After major API changes
Reassess authorization and data exposure when new endpoints or resource models are introduced.
Before new integrations
Test the trust boundary before connecting partners, external services or automated workflows.
Periodic security review
Revisit mature APIs as roles, integrations, data models and product functionality expand.
Clear scope before any interface is tested.
ShabuShabu Security performs API penetration testing only against systems included in the authorized engagement. Test environments, endpoints, credentials and restrictions are defined before the assessment begins.
Test your API before a weak permission becomes a real breach.
Tell us which API needs testing, which environments and roles are available and which integrations or workflows are most sensitive. We will structure the assessment around the real trust boundaries of your product.