Why is it important to conduct a security audit on a mobile application, even if it is for internal use?

More than a hundred vulnerabilities per day. In other words, an attack vector of gigantic proportions. Mobile apps are currently under scrutiny in the cybersecurity world due to the number of security breaches that emerge each year. They are also under scrutiny because of their enormous capacity to amplify any threat. That is why conducting a security audit on a mobile application, even if it is for internal use, has become an essential requirement for any company or developer that wants to launch a solution on the market.

The figures speak for themselves. Google Play Store, the world’s largest app store, currently has more than 3.553 billion mobile apps. Apple’s App Store, meanwhile, has 1.642 billion apps.

And the number continues to grow, representing a huge security challenge. Of course, it is also a very lucrative business: it is estimated that by the end of 2025, the mobile app market will have generated just over $610 billion internationally.

In light of all this, this article focuses on the need to secure these solutions installed on the devices of hundreds of millions of people across five continents.

Let’s start at the beginning…

1- What is a mobile application security audit?

A mobile application security audit is a systematic process that evaluates the protection mechanisms implemented in an app with three clear objectives:

• Locate vulnerabilities.
• Identify poor development practices.
• Document attack vectors and points for hostile actors.

Auditing the security of a mobile application will subject all the variables involved in its operation to a thorough examination. From the source code to communication with the API, data storage, and the use of third-party libraries.

Audits are currently performed manually or automatically. They usually consist of two phases. A static analysis (without running the app) and a dynamic analysis in which its operation is monitored in real time.

The goal in both cases is to find security gaps before cybercriminals can exploit them.

2- Phases of a mobile application security audit

Analyze, monitor, and evaluate each variable of the solution in layers to contain threats and correct vulnerabilities. A mobile application security audit examines the different layers of an app. These are the main ones:

• Source code and binary code. The DNA of any app can be the source of security problems and threats for a variety of reasons. These range from unintentional errors in the code to poor development practices, hard-coded passwords, the use of weak encryption, or the absence of input validation.
• Access control and authentication. In this case, the audit evaluates whether login mechanisms, biometric authentication, or session tokens have been implemented properly.
• Session management. Poor performance in this area can open the door to unauthorized access resulting from hijacked or unsafely expired sessions.
• Permissions and APIs. In this phase, we analyze whether the application requests more permissions than necessary and, above all, whether the APIs with which it communicates are robustly protected.
• Local storage. Identifying whether the app stores data on the device, whether it is encrypted, or whether it is possible to extract information with physical access is another of the security audit tests.
• Network communication. In this case, the analyst will be responsible for checking the use of secure communications such as the HTTPS protocol, the use of valid certificates and, of course, that no sensitive data is transmitted unencrypted under other types of protocols.
• Reverse engineering. In a mobile application security audit, it is advisable to subject the app to reverse engineering to determine whether it is possible to decompile the application to understand the code and search for vulnerabilities, thereby obtaining sensitive information.

3- How is a mobile application security audit performed?

The roadmap for this assessment is usually divided into five phases which, taken together, should provide an accurate diagnosis of the robustness and security of the mobile application.

3.1 Information gathering

In this stage of the mobile application security audit, the objectives of the application, its architecture, the technologies used, the permissions required, and the data flows are identified.

All this information is critical for properly planning the audit, identifying potential attack vectors, and prioritizing the core elements that will need to be evaluated in depth later on.

3.2 Static analysis

As explained above, static analysis of the app is performed without running the application. The audit team will inspect the binary file (.apk or .ipa).

The objective is to locate vulnerabilities, such as embedded passwords, private API keys, insecure functions, inappropriate use of encryption, or poor development practices that could compromise the security of the application.

3.3 Dynamic analysis

During this phase, the app is operated in a controlled environment using a physical device or emulator. The audit will focus on observing how the application behaves in real-time and will evaluate whether there are data leaks, storage of sensitive information, insecure communications, or poor session or authentication handling, among other variables.

3.4 Penetration testing (pentesting)

Simulate a real attack against the app to determine its resilience to threats. The idea, in this case, is to exploit previously identified vulnerabilities by testing techniques such as code injection, privilege escalation, or access to restricted functions.

This way allows the real impact of each security breach found to be evaluated.

3.5 Results report and recommendations

The final stage of the security audit will be the preparation of a report detailing the vulnerabilities identified, their level of criticality, the methods of exploitation along with evidence, and their impact.

The document will also include technical recommendations to mitigate these security holes and thus strengthen the overall security of the application.

4- Benefits of security assessment

Nowadays, developing a mass-use application and not subjecting it to a security audit is nothing short of reckless. Not doing so can be downright dangerous not only because of the reputational costs of a security crisis but also because of the penalties that the owner company would face.

The benefits, therefore, are manifold:

• Prevention of leaks of sensitive or strategic data.
• Improved trust in internal tools by employees and stakeholders.
• Avoids costs arising from attacks, legal penalties, or loss of reputation.
• Promotes good secure development practices from design to deployment.

At this point, it is worth emphasizing that applications are not static. On the contrary, they are updated and scaled, and their functionalities change. Auditing them periodically ensures that a new version does not compromise the security of the tool.

5- But… what if the app is for internal use?

Even if an application is designed for use by employees or authorized personnel, that does not mean that reputational and legal risks are eliminated.

Many cybersecurity studies and reports warn about the number of incidents that arise within a company or organization. Some are accidental, such as an employee repeatedly connecting to unsecured networks, while others are directly malicious, such as someone exfiltrating sensitive information for inappropriate uses.

In either case, a poorly protected internal app can be the perfect breeding ground for a crisis.

Any security breach in the application can compromise critical information stored in it. Or worse, it can become the attack vector for accessing the company’s internal network and, once inside, compromising its security and stealing valuable information.

In the age of remote working, mobility, and business digitization, the boundaries between internal and external have become blurred. A mobile application security audit not only allows you to anticipate threats but also strengthens the culture of resilience within an organization.

6- In conclusion

In short, subjecting a mobile app to regular and well-structured security audits is a highly recommended roadmap for protecting digital assets and, along the way, the reputation and viability of any company. At Tarlogic, we have developed a methodology to promote mobile app audit that are already helping developers avoid security incidents.

In the world of cybersecurity, prevention is always much more cost-effective than reaction.