Project Brief
- Role Security Engineer / Full-Stack Developer
- Timeline 3 Months
- Objective Eliminate OWASP Top 10 vulnerabilities from a legacy fintech application.
The Challenge
The client's legacy Node.js/React application suffered from severe security technical debt. Initial vulnerability scans revealed multiple instances of Cross-Site Scripting (XSS), insecure direct object references (IDOR), and inadequate session management that left user data exposed.
The Solution
I spearheaded a complete security refactor of the application layer. Key implementations included:
- Input Sanitization: Implemented strict validation and sanitization pipelines using libraries like DOMPurify for React and express-validator for the Node.js backend.
- Authentication Overhaul: Migrated from basic JWTs to secure, HTTP-only, SameSite cookies to prevent token theft via XSS.
- Rate Limiting & Headers: Enforced Helmet.js for secure HTTP headers and implemented IP-based rate limiting to thwart brute-force attacks.
The Outcome
Post-implementation penetration testing confirmed a 100% remediation of critical and high-severity vulnerabilities. The application's overall security posture was dramatically improved without compromising user experience or load times.