Mobile App Security Testing Practice for Developers & Non-Developers

Mobile application security testing (MAST) covers a wide range of topics, including authentication, authorization, data security, session management, and vulnerabilities for hacking. 

The mobile AST market is made up of buyers and sellers of products that identify vulnerabilities and apps used with mobile platforms during or post-development. 

But while this topic is vast, there are a few key best practices that both developers and non-developers must adhere to in order to analyze and identify security weaknesses and vulnerabilities in source code. 

Read on to discover the best practices that will help you make your mobile app more resistant to security threats. 

Common Issues Affecting Mobile Apps

Before we can take a look at the best practices for mobile security testing, let's take a look at the common issues affecting mobile apps. 

These include:

  • Using poor microservice architecture that isn’t reactive to changing threats.  
  • Implementing poor authentication checks that could be easily bypassed by malicious users or applications.
  • Storing or leaking sensitive data (albeit unintentionally) in ways that other apps can read it on the user's phone.
  • Failing to ensure that you are using safe and secure web design tools when creating your website or pages on it.
  • Transmitting sensitive data over the internet without encrypting it.
  • Using weak data encryption methods that are known to be vulnerable or easily broken.

More and more users rely on mobile development for most of their daily digital tasks, and it has become increasingly important to protect the growing amount of user data that these apps have access to, much of which is sensitive and must be protected at all costs from unauthorized access. 

With that said, here are the most effective ways to test mobile applications to find vulnerabilities in the system.

Developers' Best Practices for Mobile Security Testing

Best Practices for Mobile Security Testing for Developers

1. Assess All Open Source Codes

This is the first step to take in creating more secure apps. Open source and third-party libraries help to speed up the development and employment of mobile apps. 

Enterprise apps often contain as much as 90% open-source code. However, third-party code often has vulnerabilities that allow attackers to exploit the system remotely. Since open-source apps can be reverse engineered, it leaves your apps open to risk.

The solution is to use new and protected codes which will allow developers to build an app from the ground up, thereby reducing the possibility of anyone reverse-engineering the code. 

Moreover, you can conduct exhaustive security testing to make sure that the code will not make the mobile app vulnerable. 

You can take this a step further by staying up-to-date with the common vulnerabilities and exposures (CVEs) list so you can stay ahead of all the publicly known cyber security threats and weaknesses in open-source tools.

2. Secure the Source Code

Most of the source code in mobile app development resides with the clients. Mobile developers must consider obscuring the code to secure it from hackers. This process involves obfuscating the code to make it unclear and confusing so that attackers can't use techniques like reverse engineering to steal data. 

With such simple, yet extremely effective measures that can be taken, it’s surprising that so many retailers still leave security layers out of mobile apps, as shown in the image below: 

Secure the Source Code

You can use software tools like Pro-Guard to facilitate the process of jumbling the codebase. The software works by changing the method, class, and attribute names and turning them into meaningless characters and letters which then renders the code incomprehensible to hackers.

3. Use Strong Data Encryption

You can spend countless hours securing the source code, but if you don't have strong data encryption methods, then all your work will be for nothing.

You need to encrypt all your app data and get rid of any plain text resources to make it impossible for hackers to get insights into the mobile app. 

For optimal protection, you can use multiple security measures. The vast majority of organizations use a combination of different application security tools to encrypt data at all levels. This includes aspects related to the mobile device, data, network, database access, and so on.

4. Secure the Database

If you want people to continue using your mobile app, you need to ensure all the information pertaining to the clients remains safe. This includes payment information, user credentials, and various other sensitive data. 

To achieve this, you must maintain up-to-date security measures in your app, as well as the mobile device. 

More importantly, you must encrypt the database on the user's end in order to avoid experiencing data breaches.

This is one of the main reasons why most apps are not allowed to store information in local storage.

If data must be stored locally, it has to be secured. The app should stop any transfer of data to the outside. For instance, sending or copying sensitive information for external use should never be allowed unless authorized. 

Similarly, if any data is copied to the clipboard, it should be removed when the mobile app operates in the background.

5. Isolate App Data

Apps have to access information from mobile devices on a regular basis. But, they also need to remain independent of the data from users at all times. 

That's why it's important for app developers to focus on creating a layer of protection that protects the app’s private information. 

This feature will be pivotal in building user trust in the app - a factor that is particularly essential with regard to enterprise-deployed apps.

6. Facilitate Safe Communications

While it's important to focus on the security of the app data at its generation and storage points, it's also crucial to go beyond this and ensure the security of data on every level of transmission. 

Hackers might target the network connection between the server and mobile application, which makes it essential to begin security processes, thereby making sure that communication is secure

Make sure the app’s code can acknowledge valid security certifications while blocking any requests that are not valid. 

Qualified developers can work to eliminate illegal access from attackers by validating the authenticity of the app’s security certificates.

However, it's still important to ensure that you can send and receive data inside the app securely. This process usually involves the use of VPN tunnels, HTTPS, SSL, and TLS communication. 

These protocols are generally incorporated from the very beginning as a way to ensure safe communications at every level of data transmission.

Although HTTPS protocol is crucial in connections, it's also important to limit inbound ports. And so, developers should allow access only to secure connections as a way to help prevent attacks. 

This means that access should only be granted from the mobile app to specific services and servers. 

In fact, developers should prevent the mobile app from talking to other domains. Interactions with insecure websites can be circumvented if a white list of domain names and IP addresses can be maintained.

7. Implement Authentication Systems

In order to have a secure app, you must implement a robust authentication and authorization system. This is considered the core of any secure mobile app, which is why it's crucial to have a powerful mechanism. 

You need both aspects to function properly for the system to be at its most effective. Since data can be easily manipulated, developers must add ways for validating and authenticating that data without compromising the app’s ease of use or compatibility. 

For instance, multi-factor authentication (MFA) is often used by email marketing tools to keep your emails and personal data safe that even if your password is stolen.  This might be used to ensure that the correct information is entered by the user before the app launches or accesses any of its data.

Authorization, on the other hand, allows access to functions that users are entitled to. So, once the user displays the proper information, the mobile app determines if the user has permission to access the app data. 

With the right authentication and authorization systems built into it, it will safeguard against unauthorized access, which means that the data stored within the app will not be accessed, downloaded, or uploaded onto the server. Also, users will be locked out of the app after a set number of attempts.

Mobile Security Testing Best Practices — Summary and Takeaway 

It’s often said that perfect is the enemy of the good, and while this may be a useful maxim in many situations, it doesn’t apply to mobile security.

If mobile app security is not perfect, then that means there are possible vulnerabilities that could be exploited by a hacker or other cybercriminal. Always aim for perfection when testing mobile security.

To do this, follow the best practices for mobile security testing as outlined in the article above. If you adhere to these practices, then you can rest safe knowing that you have created truly secure mobile apps.

Published on Jan 5, 2022
Ron Stefanski
Written by Ron Stefanski
Ron Stefanski is an online entrepreneur and marketing professor who has a passion for helping people create and market their own online businesses. Since 2014, he's been able to generate over $1 million from his own business and wants to help others do the same. You can learn more from him by visiting


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