Client Overview
Our client is a fast-growing fintech start-up providing digital payment solutions for small businesses and consumers. Their platform connects merchants, banks, and users through APIs, making transactions smooth and efficient. Since their system handles sensitive financial data, ensuring strong security was a top priority.
Objective
The client engaged us to perform an API Vulnerability Assessment and Penetration Test (VAPT). Their goal was to identify and fix security issues before scaling to millions of users, ensuring compliance with financial regulations and maintaining trust.
Scope
We tested APIs responsible for:
- Payment processing
- User authentication
These APIs were exposed to public networks and handled transactions and account verifications, making them critical to the platform’s security.
Challenges
- Live Environment Testing: Since the APIs were in a pre-launch phase, we had to test without disrupting beta trials.
- Rapid Development: The API endpoints were frequently updated, requiring us to adjust our testing approach in real time.
Key Findings
During testing, we found several security risks, including:
- Broken Authentication: Weaknesses in token security that could allow unauthorized access.
- Data Exposure: Error messages revealing sensitive system details.
- Missing Rate Limiting: Lack of controls that could allow brute-force or denial-of-service attacks.
Tools and Methodology
We used a combination of manual and automated testing, including:
- Burp Suite – Intercepted and analysed API traffic.
- Postman – Sent crafted API requests to test security controls.
- OWASP ZAP – Performed automated vulnerability scans.
- Custom Scripts – Simulated real-world attack scenarios.
Our testing followed the OWASP API Security Top 10 guidelines, ensuring a thorough assessment
Collaboration and Reporting
We worked closely with the client’s development team from the beginning to understand their API setup. After testing, we provided a detailed VAPT report that included:
- Proof of Concept (PoC) – Screenshots and videos showing how the vulnerabilities could be exploited.
- Fix Recommendations – Clear steps to improve security, such as strengthening authentication and fixing error handling.
- Security Guide – Best practices to help them keep their APIs secure in the future.
The client quickly started fixing the issues, and we supported them throughout the process by reviewing patches, retesting, and sharing a final audit report to confirm everything was secured. Regular Slack updates kept communication smooth and efficient.
Deliverables
- VAPT Report: Detailed findings with PoC and solutions.
- Reaudit Report: Verification that all fixes were successfully applied.
- Attack Simulation Scripts: Provided to help the client test future updates.
Impact and Benefits
Our work handed the client a triple win:
- Enhanced Security: Critical vulnerabilities were eliminated, strengthening API security.
- Regulatory Compliance: The platform met key financial security standards like GDPR and PCI-DSS.
- Launch Readiness: With a secure foundation, the client was confident to scale their platform safely.
Conclusion
Our API VAPT helped this fintech start-up secure its platform before launch. By addressing vulnerabilities and implementing strong security measures, we ensured their APIs were ready to support growth while maintaining trust and compliance.
