In an era where digital security breaches are increasingly prevalent, conducting thorough penetration testing is essential for ensuring the resilience of desktop applications. In this blog post, we discuss a comprehensive exploration of pentesting methodologies applied to a real-world C++ desktop application in the FinTech world.
Understanding the Application
Our journey begins with a deep dive into the architecture and functionality of the target application. Developed for financial institutions, the application facilitates secure transactions and data management for thousands of users. The purpose of this application was two-fold. Firstly, it was created to generate financial trend data for the company and secondly it provided access for investors to predict future trends through a third-party API. This application did not have any Graphical User Interface (GUI) and was entirely command-line driven. Written in C++ for optimal performance, it boasts a complex codebase comprising multiple modules and dependencies.
Methodology
With the application’s intricacies in mind, our pentesting team adopted a multi-faceted approach encompassing both automated scanning tools and manual testing techniques. Leveraging industry-standard frameworks such as Nessus and Burp Suite, we meticulously examine various attack surfaces to identify potential vulnerabilities. Additionally, we conduct static and dynamic code analysis to scrutinize the underlying source code for exploitable flaws.
In order to correctly assess a desktop application, the consultant will utilise many different tools at their disposal. These tools range from traffic-sniffing to GUI manipulation and each one is vital to ensure that the security of the application has been thoroughly tested.
Vulnerabilities Discovered
Memory Corruption Vulnerabilities: Through rigorous fuzzing and input validation testing, we uncovered several instances of memory corruption vulnerabilities, including buffer overflows and use-after-free errors. These vulnerabilities, stemming from inadequate bounds checking and improper memory management practices, could potentially allow attackers to execute arbitrary code or crash the application, compromising its integrity and availability.
Insecure Cryptographic Implementations
Our analysis reveals deficiencies in the application’s cryptographic implementations, particularly in the handling of sensitive data such as user credentials, database credentials and transactional information. The developers of the application had created their own encryption to encrypt data but it was trivially reversed. Weak encryption algorithms and improper key management expose critical data to interception and tampering, posing significant risks to confidentiality and data integrity.
Once we had identified the vulnerabilities, we worked with the project managers and the development team to implement robust mitigation strategies aimed at addressing the identified vulnerabilities. These measures included:
- Enhancing input validation and bounds checking routines to mitigate memory corruption vulnerabilities.
- Employing industry-standard cryptographic libraries and best practices for secure data encryption and key management.
- Strengthening authentication mechanisms with multi-factor authentication (MFA) and secure session management protocols.
- Implementing stronger access control mechanisms to enforce least privilege principles and mitigate authorization flaws.
Authentication and Authorization Flaws
Further scrutiny of the application’s authentication and authorization mechanisms uncovered several weaknesses, including insufficient password complexity requirements and improper access control checks. These flaws could enable adversaries to bypass authentication barriers, escalate privileges, or perform unauthorized actions within the application, undermining its security posture and putting sensitive user data at risk.
Cleartext Database Connections
The application made use of an Oracle database as its primary database but due to configuration flaws, the connection from the application to the database was not encrypted, resulting in an attack known as a Man-in-the-Middle attack. The consultant was able to monitor and intercept traffic to and from the Oracle database allowing them to modify the database queries. This type of attack does require an attacker to be within the same network as the application but as we should be aware of by now, around 60% of all data breaches come from an insider-threat.