API Penetration Testing Services
Secure your API infrastructure against real-world threats. D2i Technology identifies vulnerabilities, helps prevent breaches and supports your compliance requirements.
What we test
- Authentication Strength of the mechanisms that identify callers
- Authorization Access controls, permissions and privilege boundaries
- Input validation Injection and data-tampering weaknesses
- Data exposure Sensitive information returned by your endpoints
- Transport protection HTTPS and security headers on every response
- Rate limiting Throttling that resists denial-of-service attempts
- REST + GraphQL APIs tested end to end
- 17+ Years of engineering experience
- ISO 27001 Certified information security
- ISO 9001 Certified quality management
- India + USA Global delivery
Why API Penetration Testing Matters?
APIs serve as the backbone of modern digital ecosystems, facilitating seamless communication and data exchange between different applications and services. However, their inherent complexity and interconnectedness make them susceptible to a wide range of security threats, including:
Injection Attacks
SQL or XML injection used to reach sensitive data or manipulate system behavior.
Authentication and Authorization Flaws
Weak authentication or missing checks that let attackers bypass controls.
Data Exposure
Sensitive information leaking through APIs, putting user privacy and organizational data at risk.
Broken Access Controls
Misconfigured access that allows privilege escalation and access to unauthorized resources.
Denial of Service
Floods of requests that degrade or disrupt your API infrastructure.
Security Misconfigurations
Improperly configured security settings that quietly widen your attack surface.
Not sure which APIs carry the most risk?
Our certified ethical hackers will help you decide what to test first.
API Penetration Testing Phases
Nine areas of testing give you coverage from the first request to the last response.
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Phase 1: Information Gathering
ReconCollecting data about the API architecture, endpoints and functionality.
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Phase 2: Authentication Testing
AccessEvaluating the effectiveness of authentication mechanisms.
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Phase 3: Input Validation Testing
DataIdentifying and mitigating input-related vulnerabilities.
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Phase 4: Authorization Testing
AccessAssessing access controls and permissions.
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Phase 5: Security Headers Analysis
TransportReviewing and validating security-related HTTP headers.
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Phase 6: Session Management Testing
AccessEvaluating how sessions are handled and secured.
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Phase 7: Error Handling and Logging
DataExamining error messages and logging practices.
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Phase 8: Data Integrity Testing
DataVerifying the integrity of data transmitted through the API.
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Phase 9: Rate Limit Testing
ResilienceEnsuring rate limiting and throttling mechanisms are effective.
Built for Real Business Problems
Real engagements, real outcomes. Every result below comes from a documented client case study.
Website Redesign at New Life Agency
New Life Agency needed a modern, professional website that truly reflected their reputation. D2i Technology redesigned their digital presence from the ground up — delivering a faster, more intuitive, and fully responsive experience built to support their continued growth.
Read Full Case Study of Website Redesign at New Life AgencyDevOps Transformation at ZiffyCar
ZiffyCar's peer-to-peer car rental marketplace was expanding fast — 50+ cities, thousands of hosts, and booking traffic that spiked hard every weekend. D2i Technology built the DevOps foundation to match that growth, turning a fragmented, contractor-heavy delivery model into a streamlined pipeline that achieved 10× faster releases and a 40% reduction in DevOps spend.
Read Full Case Study of DevOps Transformation at ZiffyCarCustom Web Application at Okara Enterprise
Okara Enterprises, a global logistics company, was held back by outdated systems that couldn't keep pace with the complexity of modern supply chain operations. D2i Technology delivered a cloud-based solution that saved $500K annually and transformed customer satisfaction.
Read Full Case Study of Custom Web Application at Okara EnterpriseCommon API Vulnerabilities
The weaknesses we look for in every engagement.
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1. Injection Attacks
SQL injection and command injection.
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2. Broken Authentication
Weak authentication mechanisms.
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3. Insecure Direct Object References (IDOR)
Unauthorized access to resources.
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4. Security Misconfigurations
Improperly configured security settings.
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5. Broken Function Level Authorization
Unauthorized access to privileged functionality.
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6. Excessive Data Exposure
Risk of data breaches and privacy violations from unnecessary information exposure.
Which Question Are You Asking?
Each phase answers a different question about your APIs.
| If you want to know... | Consider... |
|---|---|
| Who can call which endpoint | Authorization testing |
| If attackers can pose as legitimate users | Authentication and session testing |
| If bad input reaches your data | Input validation and data integrity testing |
| What your responses give away | Data exposure and error handling analysis |
| If a request flood would hurt you | Rate limit testing |
| If your transport settings are sound | Security headers analysis |
Our API Penetration Testing Approach
At D2i Technology, we employ a comprehensive and systematic approach to API penetration testing, leveraging industry-leading tools and methodologies to identify and address security vulnerabilities effectively. Our process typically includes the following steps:
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Step 01
Discover
Understand the scope of your API infrastructure and identify all endpoints, parameters and authentication mechanisms.
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Step 02
Assess
Systematically check for injection flaws, broken authentication, sensitive data exposure and more.
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Step 03
Test Manually and Fuzz
Manual testing and fuzzing uncover complex issues that automated scanners overlook.
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Step 04
Verify Access
Confirm that only authenticated and authorized users can reach sensitive resources.
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Step 05
Check Data
Verify the integrity and validity of exchanged data to prevent tampering and injection.
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Step 06
Check Transport
Assess security headers and transport protection such as HTTPS against eavesdropping.
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Step 07
Report
A detailed report with vulnerabilities, potential impact and actionable remediation advice.
What Happens After You Contact D2i?
No big commitment up front. Here is what the first few weeks look like.
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Step 1: 30-minute discovery call
We listen to what your APIs do and what they expose.
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Step 2: Scoping
We agree endpoints, documentation, test accounts and rules of engagement.
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Step 3: Proposal
Approach, team and estimate in writing.
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Step 4: Test plan
Schedule, access and communication paths agreed.
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Step 5: Start testing
Testing begins and critical findings are flagged early.
The Benefits of Choosing D2i Technology
Findings you can act on, and a partner that stays with you through the fixes.
Expertise and Experience
Skilled security professionals with extensive API testing experience across industries and technologies.
Customized Solutions
A testing approach shaped around your business requirements and security concerns.
Compliance and Regulatory Support
Help meeting GDPR, HIPAA, PCI DSS and similar requirements for API-enabled systems.
Continuous Support
Ongoing guidance to implement remediation and adapt to emerging threats.
Real-World Attack Simulations
We think like attackers to show what could really happen to your APIs.
Full Lifecycle Testing
Security testing across the lifecycle of your APIs, with remediation support afterward.
Compliance and Standards
Testing mapped to the guidance that matters for APIs, with evidence you can hand to an auditor.
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Scope
Map the test to the standards and APIs that are in scope.
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Test
Manual testing and fuzzing against your real endpoints.
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Evidence
Findings with impact that auditors can review.
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Report
Prioritized remediation guidance.
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Re-test
Confirm fixes hold before release.
- OWASP API Security Top 10
- API security best practices
- GDPR
- HIPAA
- PCI DSS
- ISO 27001
Techniques We Use
Manual testing and fuzzing across the areas that matter most for APIs.
Access
- Authentication testing
- Authorization testing
- Session management
- Access control checks
Data
- Input validation
- Data integrity checks
- Injection testing
- Data exposure review
Transport
- HTTPS review
- Security headers
- Transport layer protection
Resilience
- Rate limit testing
- Throttling checks
- Fuzzing
- Error handling analysis
Not Sure Where to Start?
Tell us where you are and what you need. We will suggest a starting point.
You're probably looking for
Choose a stage to see our suggestion
Your answers stay on this page. Nothing is sent until you contact us.
How Can We Work Together?
Whether you need a one-time assessment or an ongoing API security partner, we match the engagement to your APIs, budget and release cadence.
Test My APIs
A scoped penetration test with prioritized findings, remediation guidance and re-testing.
Best for: Teams with APIs to release or an audit to meet.
Extend My Security Team
Certified ethical hackers who work inside your process and tooling.
Best for: Companies that already have a security function.
Own My API Security
Recurring tests after major releases so new endpoints never reopen old risks.
Best for: Businesses that ship often and want continuous assurance.
Choose How You Pay
Dedicated Team
Monthly retainer for ongoing testing with a dedicated tester and predictable billing.
- Full-time dedicated testers
- Daily standups and sprint planning
- Maximum cost efficiency
Fixed-Price Project
For a well-defined API scope. Agree on price, timeline and milestones up front.
- Clear scope and milestones
- Fixed budget, no surprises
- Defined delivery dates
Flexible Hourly
Pay only for hours worked. Best for targeted checks, re-tests or on-demand expertise.
- No long-term commitment
- Transparent time tracking
- Scale up or down any time
Why Companies Work With D2i
Don't leave your API infrastructure vulnerable. Partner with a team that protects your critical assets.
Real-World Attack Simulations
We test the way an attacker would, to show real risk.
Certified Ethical Hackers
A team of certified professionals on every engagement.
Full Lifecycle Security Testing
Coverage from design and release through ongoing change.
Post-Engagement Support
Remediation help so fixes actually get implemented.
ISO 27001 Certified
A certified information security management system behind every engagement.
Cost-Effective Engagement
India-based expertise at up to 60% savings versus onshore teams.
What Clients Say
In recognition of exceptional performance, dedication, hard work, passion, and commitment to excellence — D2i Technology’s invaluable contribution continues to make a significant impact in support of our All Hazards, One Health, One Nature mission.
Allison A. Sakara
Co-Founder & Executive Director, High Alert Institute
Their DevOps Services in USA helped us significantly reduce deployment time and infrastructure costs. D2i Technology streamlined our CI/CD pipelines and improved system stability. The results were visible within weeks, and their DevOps expertise truly made a difference.
DevOps Services & Solutions (USA)
D2i Technology is a highly dependable Web Development Company in India. From requirement gathering to final delivery, their team demonstrated strong technical expertise and ownership. The final product was robust, user-friendly, and built exactly as envisioned.
Web Development Company (India)
Frequently Asked Questions
The questions we hear most before a project starts.
Strengthen Your API Security With Expert Penetration Testing.
Don't leave your API infrastructure vulnerable to exploitation. Partner with D2i Technology for comprehensive API penetration testing services and safeguard your critical assets against security threats. Contact us today to learn more about how we can help secure your APIs and protect your organization from potential risks.
No obligation. Start with a 30-minute discovery conversation.