API Security Testing for UK Businesses
Find and fix broken authorisation, data exposure and injection flaws in your REST, GraphQL and SOAP APIs before attackers exploit them.
Our certified engineers combine automated scanning with manual testing against the OWASP API Security Top 10 to give you a clear, prioritised remediation plan.
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About API Security
Why structured, proactive security testing is essential for your organization
Definition & Approach
An API security assessment tests how your APIs handle authentication, authorisation, input and data exposure, using the OWASP API Security Top 10 and real attacker techniques as a benchmark.
- Authentication and authorisation testing
- Input validation and injection testing
- Rate limiting and abuse-case review
Business Urgency
APIs now carry most of your application traffic and often expose sensitive data directly. A single flaw such as broken object-level authorisation can leak thousands of customer records.
Holistic Protection Across Every Attack Surface
Our testing methodologies evaluate entry points, authentication mechanisms, network boundaries, and business logic.
What our API security assessment covers
From public endpoints to internal microservices, we test the full API attack surface.
Authentication & Token Testing
Test login flows, API keys, JWTs and OAuth implementations for weaknesses.
Authorisation & Access Control
Detect broken object-level and function-level authorisation across user roles.
Injection & Input Validation
Identify SQL, NoSQL, command and XML injection through API parameters and payloads.
Data Exposure & Business Logic
Find excessive data in responses, leaking secrets and abusable business workflows.
Rate Limiting & Resource Abuse
Check throttling, quotas and resource limits to prevent denial of service and scraping.
API Gateway & Configuration Review
Review gateway, CORS, TLS and header settings and spot forgotten or shadow endpoints.
Why you need an API security assessment
Scanner alone vs Goognu hybrid
| Capability / Feature | Automated Scanners Alone | Goognu Hybrid (Auto + Manual) |
|---|---|---|
| Known vulnerability detection | ✕ Yes | Yes, verified by an engineer |
| Broken object-level authorisation | ✕ Limited | Yes |
| Business-logic and workflow abuse | ✕ No | Yes |
| Prioritised remediation guidance | ✕ Generic | Tailored to your stack |
Key Benefits of Our Security Assessments
Actionable protection designed to enhance your operational resilience and regulatory standing
Clear priorities
Findings ranked by real-world risk, not just severity scores.
Developer-friendly fixes
Reproducible requests and code-level guidance your team can act on straight away.
Audit-ready evidence
Reports mapped to OWASP, ISO 27001 and GDPR for customers and auditors.
Free retest
We verify your fixes and confirm that issues are closed.
Systematic Security Methodology
A five-step process from scoping to retest.
Scoping & Discovery
Agree APIs, environments, test accounts and rules of engagement, and map endpoints from specs and traffic.
Automated Scanning
Run authenticated scans against documented and discovered endpoints to cover known weaknesses.
Manual Testing
Our engineers test authorisation, business logic and chained attacks that tools cannot find.
Reporting & Debrief
Deliver findings ranked by risk and walk your team through remediation.
Retest
Re-test fixed issues and confirm they are closed.
What You Receive Upon Completion
Clear, executive-level summaries paired with granular remediation guidance for your engineering teams
Executive summary
A short, plain-English view of your API risk and next steps.
Technical report
Every finding with evidence, request and response samples, and step-by-step remediation.
Retest letter
Confirmation that critical and high issues have been fixed.
Strengthen Your Security Posture Today
Don't wait for a high-profile security breach or compliance violation to expose vulnerabilities in your systems.
Goognu's certified security specialists deliver actionable, zero-false-positive assessments tailored to your environment. Contact our security team today for a confidential, no-obligation scoping session.
API Security FAQs
Common questions about scoping, methodologies, testing windows, and deliverable reports
Have custom compliance or audit requirements?
Our team routinely tests against ISO 27001, SOC 2, PCI-DSS, Cyber Essentials Plus, and GDPR standards.
Consult with our security engineers