Multi-National Banking Platform Assessment
Comprehensive security testing of an online banking platform serving millions of customers across the UK
The Challenge
A major UK financial institution required comprehensive security testing of their online banking platform serving millions of customers. The platform handled sensitive financial data and required compliance with PCI DSS, FCA requirements, and UK data protection regulations.
The client needed to ensure their platform could withstand sophisticated attacks while maintaining regulatory compliance and customer trust. With the increasing sophistication of financial cybercrime, identifying vulnerabilities before deployment was critical to protecting customer assets and meeting stringent regulatory requirements.
Our Approach
We conducted a multi-faceted security assessment targeting all critical components of the banking platform:
Web Application Penetration Testing
Comprehensive testing across all customer-facing interfaces including account management, transaction processing, and customer support portals. We tested for OWASP Top 10 vulnerabilities, business logic flaws, and authentication weaknesses.
API Security Assessment
Security assessment of internal and partner integrations, focusing on authentication mechanisms, authorization controls, data validation, and rate limiting. We tested both REST and GraphQL endpoints used for mobile banking and third-party integrations.
Authentication & Session Management
In-depth review of multi-factor authentication implementation, session handling, password policies, and account recovery mechanisms. We tested for session fixation, session hijacking, and authentication bypass vulnerabilities.
Payment Processing Workflow
Security analysis of payment processing workflows, including domestic and international transfers, bill payments, and standing orders. We examined transaction validation, authorization controls, and audit logging.
Key Findings
- 15 Critical and High-Risk Vulnerabilities: Identified across the application stack, including several that could have led to unauthorized account access
- Authentication Bypass in Partner API: Discovered a critical flaw allowing unauthorized access to customer data through a third-party integration endpoint
- SQL Injection in Legacy Components: Found multiple SQL injection vulnerabilities in legacy backend systems that could expose sensitive customer information
- Insecure Direct Object References: Identified IDOR vulnerabilities allowing access to other customers' transaction histories
- Insufficient Rate Limiting: Discovered endpoints vulnerable to brute force and enumeration attacks
- Sensitive Data Exposure: Found instances of PII and financial data being logged in plain text
Remediation & Retest
We provided a detailed remediation roadmap with prioritized recommendations based on risk severity and business impact. Our report included:
- Proof-of-concept exploits demonstrating each vulnerability
- Detailed technical descriptions for development teams
- Specific code-level remediation guidance
- Compliance mapping to PCI DSS and FCA requirements
- Security architecture recommendations for long-term improvements
After the client implemented fixes, we conducted a comprehensive retest to validate all remediation measures. All critical and high-risk vulnerabilities were successfully resolved, with improvements to the overall security posture.
Impact & Outcome
The platform was secured before public launch, preventing potential data breaches that could have resulted in significant financial losses, regulatory penalties, and reputational damage. The client successfully met all FCA and PCI DSS compliance requirements, enabling a confident launch to market.