Securing a Mobile Banking App: Lessons from SAST and SCA Scans

Introduction

Mobile banking applications are a prime target for cyber threats due to the sensitive financial data they handle. A financial institution recently developed a mobile banking app using Java for backend services and JavaScript for frontend interfaces. As part of their security strategy, the development team integrated a leading software vulnerability application platform to conduct Static Application Security Testing (SAST) and Software Composition Analysis (SCA) scans. The results were eye-opening, revealing multiple security flaws that could have been exploited by attackers if left unaddressed.

The Findings: Uncovering Critical Vulnerabilities

During the initial testing cycles, the security platform identified numerous vulnerabilities within the mobile banking app, specifically in three key areas:

1. Online Transactions

The security scans exposed SQL injection vulnerabilities in the app’s transaction processing system. The backend was not properly sanitizing user inputs, leaving the database exposed to injection attacks that could allow attackers to manipulate financial transactions, access unauthorized data, or even delete critical records.

2. Account Access

The scans also detected hardcoded credentials within the source code. Developers had inadvertently stored authentication tokens and API keys directly in the codebase, significantly increasing the risk of unauthorized access in case of a data breach. Hardcoded credentials are a known attack vector that cybercriminals actively search for when targeting banking applications.

3. Authentication Mechanisms

The app’s authentication system relied on outdated third-party dependencies, some of which contained known security vulnerabilities. These outdated dependencies introduced weaknesses that attackers could exploit to bypass login security, steal user credentials, or escalate privileges within the system.

The Challenge of Prioritizing Remediation

With a growing list of security concerns, the QA Director faced a significant challenge: determining what to fix first. The application development team struggled to prioritize remediation due to competing priorities from business stakeholders, compliance teams, and product managers pushing for feature releases. Without a structured approach, deciding which vulnerabilities posed the greatest risk and required immediate attention became a daunting task.

Confusion Among Teams

The lack of clarity around remediation priorities also caused friction within the development team. Some team members focused on addressing easier-to-fix issues, while others tackled high-impact but complex vulnerabilities. The lack of a defined roadmap created bottlenecks in the development process, delaying security fixes and putting the application at risk.

Implementing a Structured Approach with RACI

While the company had a robust regression and security testing plan in place for every new release, the testing cycles were not enough to prevent recurring security flaws. The missing link was a clear accountability framework that defined who was responsible for each step in vulnerability detection, prioritization, and remediation.

By implementing a RACI (Responsible, Accountable, Consulted, and Informed) matrix within a specialized tool like ezRACI, the team could greatly benefit in the following ways:

1. Clarity in Remediation Ownership

   • The RACI matrix would clearly define who is responsible for fixing security vulnerabilities (developers), who is accountable for ensuring they are resolved (QA Director), who needs to be consulted (security analysts), and who must be informed (compliance and business stakeholders).

2. Prioritization of Security Issues

   • By mapping vulnerabilities based on risk level and regulatory compliance requirements, the team could focus on fixing the most critical security flaws first rather than tackling them randomly.

3. Prevention of Recurring Security Flaws

   • Using ezRACI, the organization could track past security issues, assign responsibility for ongoing risk mitigation, and ensure that lessons learned were incorporated into future development cycles.

4. Better Cross-Team Communication

   • The structured framework would enable seamless communication between development, security, QA, and compliance teams, ensuring that all stakeholders were aligned on security priorities.

Conclusion: A Path Toward Sustainable Security

While security testing tools like SAST and SCA scans are essential for identifying vulnerabilities in a mobile banking app, a well-defined remediation strategy is equally critical. The implementation of a detailed RACI matrix using a tool like ezRACI would provide the team with a structured approach to vulnerability management, ensuring that security issues are addressed efficiently and do not reoccur in future releases.

By embracing a structured framework for security responsibility and prioritization, organizations can accelerate vulnerability remediation, reduce security risks, and maintain trust with their customers—all while ensuring that their mobile banking applications remain resilient against cyber threats.