Pentesting a Fintech Company

The Engagement

The Fintech Company

NextdoorSEC was hired by a prominent fintech company that offers a user-friendly mobile application for financial transactions and investments.

The company had established a strong reputation for its secure and efficient services but wanted to ensure its app was robust enough to withstand potential cyber threats. To address this concern, they sought NextdoorSEC’s expertise in conducting comprehensive penetration testing.

The Objective

The primary objectives of the penetration testing carried out by NextdoorSEC were as follows:

External Penetration Test
  • Emulating a real-world attack from external sources, mimicking the tactics of malicious hackers without prior knowledge of the fintech app.
  • Attempting to identify and exploit security vulnerabilities in the app’s public-facing components.
  • Assessing the app’s resilience against potential Distributed Denial of Service (DDoS) attacks and data breaches.
Internal Penetration Test
  • Simulating an “insider threat” scenario to evaluate the app’s defence mechanisms against potential malicious actions by internal personnel or compromised accounts.
  • Gaining access to sensitive data or administrative controls without raising any suspicion.
  • Assessing the overall security posture of the app’s internal infrastructure.

The Testing Methodology

NextdoorSEC employed manual and automated testing techniques, utilizing cutting-edge tools commonly used by cybercriminals. The testing approach was designed to replicate real-world scenarios and accurately assess the app’s security.

The testing process was conducted in a controlled environment, ensuring no harm to the production system or user data. NextdoorSEC conducted the tests from a ‘blackbox’ perspective, with no prior knowledge of the app’s internal architecture, mirroring the approach of genuine cyber attackers.


✅ Weak Account Lockout Policy

The fintech app lacked a robust account lockout policy, leaving it susceptible to brute-force attacks on user accounts.

Insecure Data Storage

User data, including personal information and financial records, was inadequately protected in the app’s storage, making it vulnerable to unauthorized access or data leaks.

Lack of Input Validation

The app lacked proper input validation, making it susceptible to SQL injection attacks, which could lead to unauthorized access to the database.

Unencrypted Communication

Communication between the app and the server was not adequately encrypted, potentially exposing sensitive user data to interception during transmission.

Insufficient Session Management

Weak session management allowed for session hijacking and impersonation, enabling attackers to gain unauthorized access to active user sessions.

Misconfigured Access Controls

Certain parts of the app granted excessive privileges to unauthorized users, potentially leading to unauthorized account takeovers or data manipulation.

Exposed Debugging Information

The app unintentionally exposed debugging information, which could aid attackers in exploiting the app’s vulnerabilities.

Vulnerable Third-Party Integrations

The penetration testing revealed vulnerabilities in some of the third-party integrations utilized by the fintech app. Specifically, specific integrations, such as payment gateways and analytics services, were found to have security weaknesses. Malicious actors could exploit these vulnerabilities to gain unauthorized access to sensitive financial data or disrupt the app’s functionality.

✅ Bypassing Multi-Factor Authentication (MFA)

The MFA system was found to be susceptible to being bypassed, allowing attackers to gain unauthorized access to user accounts without completing the required additional authentication steps.

Don't let the cyber crooks beat you to the punch!

Let us help you secure your e-commerce business before they have a chance to get their grubby little hacker hands on them.

Word on the street

We're not like average security penetration testing companies. We've earned a reputation for delivering tailored solutions to businesses of all sizes. From mom-and-pop shops to tech startups, our expertise keeps your data safe and sound. Our clients appreciate our customized approach and commitment to transparency. Join the Nextdoorsec fam, one of the reliable vulnerability assessment companies and rest easy knowing your security is in good hands.

Nextdoorsec is an exceptional security company that provides thorough and detailed reports that are easy to understand. Their team is highly knowledgeable and responsive, always willing to answer any questions and provide guidance on how to properly address security vulnerabilities according to industry best practices. With Nextdoorsec's help, we were able to identify and address previously undetected security gaps in our systems, giving us greater confidence in our overall security posture. We highly recommend Nextdoorsec for any organization looking to improve their security posture and protect their valuable assets.

Pieter van der Meer
Cloud Architect

Nextdoorsec provided our organization with top-notch security services. Their team was incredibly thorough and professional, and their level of communication was outstanding. They kept us informed at every step of the process and were always available to answer any questions we had. We were particularly impressed with their commitment to transparency and their ability to provide actionable recommendations for improving our security posture. We would highly recommend Nextdoorsec to any organization looking to enhance their security and protect their valuable assets.

Lars Jansen

Contact Us


Antwerp, Belgium

Get Started

Are you prepared to beef up your cyber defenses and soar to new heights in the digital world?