Mobile Application Penetration Testing: Complete Guide & Best Practices

The mobile app industry has been booming in recent decades and shows no sign of stagnation. The market, valued at over $250 billion in 2023, is projected to grow at an impressive CAGR of 14,3% from 2024 to 2030. However, the industry’s advancement comes with ever-evolving security risks, requiring businesses to improve their testing strategies. 

That said, detecting potential vulnerabilities in your mobile application has never been more critical. Without checking whether your app is resistant to possible attacks, you put yourself at risk of enormous financial and reputational losses. Luckily, you can avoid this outcome and strengthen your solution’s security measures with mobile application penetration testing. This proven security assessment involves simulated attacks to spot common vulnerabilities and verify your application’s protection is sufficient. 

In this article, Iterasec experts will explain the most common techniques, methodologies, and best practices for effective mobile pentesting. Ready? Let’s jump right in!  

What is Mobile Application Penetration Testing?

Mobile app penetration testing is a comprehensive security checkup that aims to discover an iOS or Android application’s most critical weaknesses by targeting it with imitated attacks. 

Thanks to this approach, it’s possible to assess the most significant components of your solution and see whether your security practices are effective enough to withstand particular breaches or cyberattacks. You can also discover whether your app can resist threats like unauthorized access or functionality manipulation.

With the help of a mobile app pentest, you can determine and mitigate the most critical security risks and areas an attacker would most likely target. This information will let you fix issues with your APIs, features, or authentication methods and take your app’s security to the next level.  

Why Mobile App Pentesting is Important

Before diving into the most compelling reasons to run mobile application pentesting, let’s examine several eye-opening facts. 

• The global average cost of a data breach reached over $4.8 million, as the latest IBM security report states.
• In the third quarter of 2023 alone, more than 438,000 mobile malware installation packages were detected.
• Almost 25% of businesses integrating AI-based solutions into their mobile apps admitted that security, risk, and governance were their most significant concerns, as Forrester’s 2024 State of Application Security report claims.

So, given the alarming trends in mobile app security, why is penetration testing vital? Here are the most significant advantages of conducting such tests:

• Detect vulnerabilities. Your app’s weaknesses may go unnoticed if you don’t conduct regular checkups. Thanks to penetration testing, it’s possible to identify vulnerabilities and debug your application proactively, ensuring that cybercriminals won’t be the first to find gaps in your security system.

• Protect sensitive data. Conducting a thorough pentest is essential if your app stores sensitive customer data, such as financial or health-related information. It’s one of the most effective ways to prevent insecure data storage practices, access control issues, and more.

• Stay compliant. These days, keeping your digital solution compliant with specific user privacy or security regulations is paramount. Run a penetration test to check whether your mobile app sticks to GDPR, HIPAA, etc.

• Safeguard API integrations. APIs are among the most common targets of cybercriminals striving to compromise your system. A mobile app penetration test will show whether your API integrations have all the required security measures to prevent unauthorized access to your app’s data and functionality.

• Earn customer trust. According to a survey, nearly 43% of mobile app users prioritize security over functionality and convenience. When choosing an application for their needs, most people must know their private data will be safe. With a penetration test, you can guarantee your solution is reliable and trustworthy.

What Can a Mobile App Pentest Detect?

Mobile penetration testing can identify numerous potential weaknesses. Of course, it mainly depends on the test‘s purpose and techniques (more on that in a bit). But here, let’s consider the most common mobile app issues and vulnerabilities you can detect with the help of penetration testing.

• Unprotected data storage: the potential unauthorized access to databases containing sensitive user information or financial data
• API vulnerabilities: weak encryption or authentication leading to functionality manipulation and other security issues
• Deep Links exploitation: vulnerabilities related to insecure deep links allowing attackers to gain unauthorized access to the application
• Platform-related risks: security flaws specific to a particular mobile app platform, such as iOS or Android
• Access and permission issues: weaknesses associated with poor intent management, which may result in functionality manipulation or sensitive data leakage
• Insecure authentication: compromised passwords and PINs that cause identity theft, financial loss, and data exposure
• Poor input validation: a critical vulnerability that allows attackers to inject malicious code and compromise the application’s functionality

With thorough penetration testing, you can prevent these and many other security vulnerabilities, making your mobile application persistent in front of the evolving landscape of cyber threats.

Mobile App Penetration Testing Methodology

The methodology required for a result-driven mobile app penetration test varies depending on your app’s specifics, the inspected areas, and the chosen approach. However, our experience shows that a comprehensive mobile application pentest has four critical stages. Of course, each of them consists of some additional steps. Plus, there are specific tools, techniques, and frameworks used throughout every phase. 

Pro tip: It’s worth turning to frameworks and guidelines for consistent and efficient security testing when conducting mobile application penetration tests. These include the following:

• OWASP Mobile Top 10 — includes the ten most significant mobile app vulnerabilities.
• OWASP Mobile Application Security Testing Guide (MASTG) — contains valuable tips, methodologies, and frameworks for mobile app testing.
• OWASP Mobile Application Security Testing Standard (MASVS) — provides a framework for mobile app security controls and criteria.
• OWASP Mobile Application Security Cheat Sheet — offers trips and tricks regarding crucial mobile security practices.
• Mobile Application Security Assessment (MASA) — gives security guidelines and testing criteria for specialists verifying mobile apps on Google Play.
• NIAP — categorizes functional and security requirements for mobile applications.

Now, let’s break down the general mobile app pentesting methodology:

Step 1. The Discovery Phase

At this stage, the team prepares to conduct a test and collects all the necessary information about your app. Usually, it involves the following penetration testing techniques:

Static Analysis of a Mobile App

Checking the app’s source code is one of the initial steps of the penetration testing process. Static Application Security Testing (SAST) handles application code review without executing it. If your app has vulnerabilities like hardcoded credentials, backdoor entries, or insecure coding practices, specialists can detect them at the earliest testing stage. 

Open-Source Intelligence Assessment

Open-source intelligence (OSINT) involves a detailed analysis of all publicly available information about a mobile application. The experts explore everything from social media posts and comments to developer platforms and forums. 

But what does this information have to do with a penetration test? The thing is that cybercriminals may also gather data about your application to identify its weakest points and potential target areas. For example, it’s possible to find a Reddit post where a user complains about a specific vulnerability or certain functionalities described on a forum.

Mobile Network Traffic Testing

Before jumping into a mobile app penetration test, it’s a good idea to check communication protocols and endpoints that may expose confidential data. Our team analyzes network traffic using different tools, specially adapted for the unique needs of our clients. 

Step 2. Analysis and Evaluation

The next step is the most complex and significant — a team of security experts analyzes your mobile app on multiple levels to check its code, architecture, and integrations for possible vulnerabilities. Here’s a more detailed look at the aspects inspected and tools used throughout this process.

Static and Dynamic Code Analysis

Once again, a static application security test takes place — but this time, it’s more detailed and meticulous than during the discovery phase. Thanks to this approach, testers detect security flaws and application weaknesses, including SQL injection vulnerabilities and data storage security issues. 

Besides, that’s where dynamic security testing steps in. It verifies the app’s runtime behavior, allowing specialists to imitate realistic interactions. Thus, you can see how the app reacts to possible threats, including the following:

• Input validation problems: Data manipulation or injection attacks become possible due to unsanitized user input.

• Cross-site scripting: An attacker attaches malicious code to compromise user-app interactions.

• Inter-Component Communication (ICC) flaws: The application’s communication with specific components or servers is insecure, opening up opportunities for unauthorized access.

Architecture Assessment

The application’s architecture covers backend elements, databases, and authentication mechanisms. Security issues related to these essential components of your app mean that the whole system can be compromised. Therefore, it’s crucial to pay extra attention to this penetration testing stage, which usually addresses the following vulnerabilities:

• Misconfiguration in security settings: If your backend servers or cloud lack proper security measures, your app might fall victim to data exposure.
• Faulty authentication and authorization mechanisms: If your application’s authentication and authorization protocols don’t work correctly, unauthorized access issues may occur.
• Unprotected data storage: Sensitive customer data requires reliable and secure storage with solid encryption. Otherwise, it’s easier for cybercriminals to compromise it.

Reverse Engineering

Reverse engineering is a technique cybersecurity experts and software developers use to understand how a particular system or application functions by analyzing it backward from its final form. In mobile application penetration testing, professionals use reverse engineering to spot vulnerabilities hidden under the app’s surface.

For instance, this approach is necessary when looking for issues related to obfuscated code. While developers usually implement obfuscation to protect the app, it may also hide security flaws. Besides, reverse engineering is efficient when testers examine custom libraries and frameworks with specific internal workings.

Analysis of Local Data Storage 

If your app stores some data locally on users’ mobile devices, it may be vulnerable to particular security issues, from sensitive data exposure to unauthorized access gained through other applications. 

Therefore, during mobile pentesting, professionals should examine whether the app’s data can’t fall into the wrong hands. In particular, certain information leaves traces (remnants) even after a user removes it from the device. Testers can spot these traces and check whether they impact the app’s security with the help of various penetration testing techniques, such as forensic analysis. 

Besides, it’s essential to check whether the mechanisms related to user privacy (like sandboxing) work properly. This way, you ensure that nobody can get around them and gain access to the app’s confidential data.

Inter-Application Communication Checkup

How your application communicates with other apps (in particular, when exchanging data and interacting through specific functionality) also impacts its security. Testers should also check these aspects to see whether data sharing and access don’t translate into security weaknesses.

One potential vulnerability is insecure or faulty inter-process communication (IPC). Pentesters should determine whether proper authorization checks, adequate data transmission, and other crucial aspects function as expected. In particular, inappropriate access permissions also pose a significant risk, as they sometimes let an app access sensitive data from other applications.

Step 3. Exploiting the Application

It’s time to imitate real-world attacks targeted at your mobile application to see how it reacts to cyber threats. Security experts usually simulate unique exploits tailored to your application’s functionality, architecture, and other specifics. Alternatively, it’s possible to use ready-made tools to “attack” an application striving to detect and eliminate typical vulnerabilities. 

Again, the approach here varies depending on your various factors, including your application’s type, the data it operates on, and the hired specialists’ testing approach. 

For example, during black box pentesting, experts have no access to the app’s data, which lets them check whether it’s resistant to realistic attacks. Meanwhile, gray box testing involves partial access (such as standard user credentials) to detect internal and external weaknesses. Finally, with the white box approach, testers gain full access to the app’s data to conduct a comprehensive system checkup.  

For more details regarding the difference between black box, gray box, and white box testing, check out our recent blog post on the topic.

Step 4. Reporting Test Results

When the main part of your mobile app penetration test is complete, the team that conducted it prepares an in-depth report regarding the outcomes of their work. Usually, it contains the following details:

• The information regarding the tested application components
• The testing methodology used
• The identified weaknesses with their security levels (such as MAS-L1, MAS-L2, and MAS-R, according to OWASP Mobile Application Security Verification Standard)
• The simulated exploits testers have used to showcase vulnerabilities
• Guidelines on how to fix the identified vulnerabilities and improve the application’s security

Pro tip: Consider running additional mobile pentesting for your app regularly. This way, you will see whether your fixes have been effective. Besides, it’s possible to detect and address newly emerged issues proactively.

Top 8 Best Practices for Mobile Application Penetration Testing 

There is no general-purpose approach to penetration testing for mobile apps that would fit all possible needs. However, most testing teams use some valuable techniques and practices to maximize the effect of application security checkups. Here are some practical tips and tricks for running a mobile app pentest that hits the mark.

1. Specify Your Pentesting Goals

You should clearly understand what you aim to achieve with penetration testing. Whether you want to evaluate all the app’s components or focus on some specific vulnerabilities, such as issues with architecture or APIs, define it before testing begins. Also, clarify your security requirements, expected scope of work, and other nuances.

2. Choose the Most Suitable Testing Tools and Techniques

As mentioned, testing techniques vary depending on your app and the objectives of the planned pentest. With that in mind, pick the most suitable toolkit for your assessment. No worries — an experienced testing team like Iterasec is here to help you out. We can provide detailed consultation and assist you in choosing the most appropriate penetration testing techniques for your mobile app.

3. Conduct a Comprehensive Penetration Test

If you want to detect various weakness types, it’s worth inspecting your app on multiple levels. Testers should identify issues on different operating systems (iOS, Android) and devices, looking for platform-specific vulnerabilities and other possible challenges.

4. Verify Integrations and APIs

Without robust security measures and regular checkups, third-party services and APIs are among the most common targets for cybercriminals. Therefore, it’s essential to verify these aspects of your mobile application thoroughly.  

5. Look for Vulnerabilities in Data Storage and Transmission

Your mobile application’s data storage is another vital component commonly targeted by cybercriminals. Pay special attention to the security of your app’s databases, communication protocols, and encryption standards. That’s particularly important when dealing with sensitive information, from user credentials to financial data and medical records.

6. Assess Your App’s Architecture

Whether using a cloud-based, hybrid, or traditional approach, protecting your mobile application’s architecture is paramount. During a penetration test, experts should verify that authentication, authorization, and security settings have no flaws that would allow attackers to gain unauthorized access to your app’s confidential data.

7. Provide Regular Security Updates and Patches

If user privacy and data protection are among your top priorities, ensure consistent security updates. This way, you will safeguard your users from emerging vulnerabilities that malicious actors might exploit. Penetration testing is an excellent way to determine what security updates are necessary to guarantee peace of mind.

8. Plan Your Remediation Steps

After your mobile penetration test is complete, remember to create a detailed report summarizing your findings. It should also include remediation guidelines to help developers, testers, product owners, and other stakeholders eliminate the identified vulnerabilities.

Discover even more valuable tips in our detailed guide on penetration testing best practices.

What is the Cost of a Mobile Application Pentesting?

Mobile app penetration testing cost varies due to numerous aspects. Most often, the price depends on the following factors:

• Mobile application’s complexity. If your app is relatively small and has only basic functionalities, security experts will test it much faster. As a result, the price of penetration testing will also be lower. In contrast, an app with multiple features and complex architecture requires more time, money, and resource investments.

• Testing scope. The price also depends on the chosen testing type and methodology, which varies based on your goals. Identifying common weaknesses is easier (and cheaper) than conducting a comprehensive analysis of the entire system.

• The experience of the testing team. If you hire inexperienced specialists, their services will likely cost less than those of an expert testing agency. However, trying to save here is not a good idea. When dealing with specialists who lack expertise, some critical vulnerabilities may go unnoticed, costing you even more in the long run. 

Mobile Application Penetration Testing: The Bottom Line

It’s hard to overestimate the importance of mobile penetration testing for your application’s security. Detecting critical vulnerabilities, flaws, and possible attack surface will let you respond to threats before they cause any damage and take proactive cybersecurity measures. 

In-depth penetration testing covers all crucial app components, including source code, database storage, architecture, network traffic, and authorization mechanisms. With its help, it’s possible to detect various weaknesses and prevent multiple types of risks, from injection attacks and manipulation to unauthorized data access and identity theft. 

However, efficient testing requires the involvement of skilled security experts. We at Iterasec provide all types of pentesting services for mobile applications. Whether you need to check your API security, examine data encryption, or run a complete system evaluation, we’re ready to handle it. Get in touch now — let’s talk about your penetration testing needs in detail!