API Penetration Testing & API Security Testing
Protect what matters with API Penetration Testing & API Security Testing
APIs power your apps, partners and integrations — and they’re now the most attacked part of most modern platforms. Because APIs expose business logic directly, a single broken authorisation check can leak every customer’s data. Aesparrow’s API Security Testing (API VAPT) is built around the OWASP API Security Top 10 and goes deep on the flaws automated tools consistently miss: broken object-level authorisation (BOLA/IDOR), mass assignment, and business-logic abuse.
We test REST, GraphQL and SOAP APIs the way an attacker would — enumerating objects, tampering with tokens, and chaining authorisation gaps into real impact. Using your Swagger/OpenAPI definitions (or discovering endpoints ourselves), we validate authentication, authorisation, rate limiting and data exposure across every route, then hand you verified, developer-ready findings and re-test the fixes for free.
- Certified senior practitioners
- Audit-ready reporting
- Free re-test included
API Penetration Testing & API Security Testing — done right, the first time.
Senior practitioners. Verified findings. Free re-test.
Overview
API Security Testing is an authorised, in-depth assessment of your API layer — authentication, authorisation, input handling, rate limiting and business logic. Because APIs expose data and functionality directly, small authorisation gaps can have outsized impact. We combine endpoint discovery, token and session analysis, and manual exploitation to find and prove the issues that matter.
What we test for
Built around the OWASP API Security Top 10 and the realities of modern API design.
- Broken Object Level Authorisation (BOLA/IDOR) — the #1 API risk
- Broken authentication — weak JWT/OAuth flows, token handling
- Broken function level authorisation — admin actions exposed to users
- Mass assignment — over-permissive object binding
- Excessive data exposure — over-returning sensitive fields
- Lack of rate limiting — and resource exhaustion
- Injection & SSRF — across parameters and payloads
- Business logic abuse — workflow and pricing manipulation
- Security misconfiguration — CORS, verbose errors, gateway rules
- GraphQL-specific issues — introspection, batching, deep queries
Our testing methodology
Discovery & spec review
We ingest Swagger/OpenAPI or enumerate endpoints, roles and auth flows.
Authentication analysis
JWT, OAuth 2.0 and session tokens examined for weaknesses and bypass.
Authorisation testing
Systematic BOLA/BFLA testing across objects, roles and tenants.
Manual exploitation
We chain findings into real impact — data access, privilege escalation.
Reporting & triage
Verified findings with CVSS, evidence and remediation guidance.
Remediation re-test
Fixes verified and the report updated at no extra cost.
Framework mapping
- OWASP API Security Top 10 — the API-specific risk baseline
- OWASP ASVS — verification requirements for API controls
- NIST SP 800-115 — technical assessment methodology
- MITRE ATT&CK — techniques for adversary-style testing
Deliverables
Executive summary
API risk posture and priorities for leadership.
Technical findings
Endpoint, request/response evidence and root cause.
Risk ratings & CVSS
Impact-based severity you can act on.
Remediation guidance
Concrete fixes for your API and gateway config.
Re-test report
Verification that issues are genuinely resolved.
Compliance mapping
Evidence aligned to SOC 2, ISO 27001 and PCI DSS.
Why choose Aesparrow for API VAPT
- 1
OWASP API Top 10 depth
BOLA, mass assignment and function-level auth tested by hand.
- 2
REST, GraphQL & SOAP
Coverage across every API style your platform ships.
- 3
Auth & token expertise
JWT, OAuth 2.0 and session flows scrutinised end to end.
- 4
Free remediation re-test
We verify fixes and update the report so you can prove closure.
If your product is API-first, your security testing should be too. Talk to us about an API VAPT scoped to your endpoints, authentication model and release cadence.
Why API Penetration Testing & API Security Testing matters
Independent research on the cost and causes of breaches — the risks this service helps you reduce.
US$4.44M
global average cost of a data breach in 2025.
241 days
mean time to identify and contain a breach in 2025.
20%
of breaches began with exploitation of a vulnerability, up 34% in a year.
Frequently Asked Questions
Do you test REST, GraphQL and SOAP APIs?
Do you need our API documentation to test?
What is BOLA and why does it matter so much?
How do you handle authentication during testing?
Is remediation re-testing included?
Ready to secure your business with API Penetration Testing & API Security Testing?
Book a free, no-obligation consultation with an Aesparrow practitioner. We’ll scope your needs, explain the approach, and share indicative timelines — no sales script.
Standards & references
Related services
Guides & answers
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Let’s find the gaps before someone else does.
Tell us what you need tested for a fixed-scope quote, or talk it through with an Aesparrow practitioner — no obligation, no sales script.