What is the OWASP Mobile Application Security Testing Guide (MASTG)?

With millions of apps being released every day and ever-changing feature additions, it is more important than ever for enterprises to focus on security to prevent data breaches. According to Checkpoint, in 2020, 97 percent of enterprises were confronted with mobile threats employing a variety of attack vectors. 

What is Mobile Application Security Testing Guide (MASTG)?

The MASTG is a comprehensive manual for mobile app security testing. It is based on security testing and reverses engineering for iOS and Android mobile security testers.

This guide is all about setting standards for OS security testing. It comes with many of the following features:

1. Mobile platform internals

The OWASP mobile security application testing guide follows different security requirements that are outlined for the development and security testing of the mobile application. The guide includes different procedures such as penetration testing and others to examine the potential security threats found in the app. 

2. Security testing in the mobile app development lifecycle

Security testing is an important part of mobile app development. It is done throughout the phase of the development of the app. Black-box testing, White-box testing, and Gray-box testing and conducted to explore all the possible information and exploit vulnerabilities. 

3. Basic static and dynamic security testing

Static application security testing (SAST) is a testing procedure that checks the mobile application from the inside out. Whereas Dynamic application security testing (DAST) checks the mobile application from the outside, examining its current running state and discovering security threats.

Good Read: What is Mobile App Security and its best practices

4. Mobile app reverse engineering and tampering

Reverse engineering a mobile application is the procedure that follows the analysis of the compiled app for extracting information regarding its source code. Tampering follows the procedure of changing a mobile application or its environment to alter its behavioral patterns.

5. Assessing software protections

Software protection assessments are used to avoid malicious activities taking place on the software. This assessment includes routines for evaluating requirements for documentation and risk assessment, leading to data protection. 

6. Detailed test cases that map to the requirements in the MASVS

You cannot compromise with mobile data safety! Get comprehensive test cases in compliance with the Mobile AppSec Verification Standard in the OWASP Mobile Security Testing Guide.

Key Areas in Mobile App Security

Key Areas in Mobile App Security


Mobile apps differ from web apps in that they have a smaller attack surface and hence higher protection against cyber threats. To improve mobile app security, we must prioritize data protection on the mobile and the network. Given below are the key areas in mobile app security. 

1. Local data storage

When creating mobile apps, you must exercise extreme caution when storing user data. If an app inappropriately exploits operating system APIs like local storage, it may expose sensitive data to other apps running on the same device.

2. Authentication and Authorization

The endpoint handles the majority of the authentication and authorization logic. Unlike web apps, the users unlock mobile apps using user-to-device authentication capabilities like fingerprint scanning, instead of entering complex passcodes. Security testers must keep in mind the benefits and drawbacks of various authorization systems.

3. Communication with endpoints

Mobile devices provide the door to a wide range of network-based assaults, from simple to complex. Therefore, apps must use the TLS protocol to establish a secure, encrypted channel for network connection. Maintaining the integrity of information sent between the mobile app and distant service endpoints is critical.

4. Interaction with the mobile platform

Mobile operating systems have greater inter-process communication tools (IPC tools), allowing apps to exchange signals and data. These platform-specific capabilities have their own set of drawbacks. If IPC APIs are utilized incorrectly, confidential data may be inadvertently exposed.

5. Code quality and exploit mitigation

Because of the smaller attack surface, mobile apps have a lesser attack surface than online apps. Owasp cross-site scripting is potentially conceivable in some instances on mobile. Therefore, you must follow practices for security, creating secure release builds.

6. Anti-tampering and anti-reversing

Because software protection features are frequently utilized in the mobile app market, security testers must learn how to get around them. Client-side protections have a benefit, provided you implement them with reasonable expectations in mind and are not utilized to substitute security controls.

MASTG will guide you in focusing on these key areas. 

Mobile App Taxonomy

Any software that runs on a mobile device is referred to as a "mobile app." The following are some examples of mobile apps:

1. Native app

A native app is a software program, developed for usage on a particular platform or device i.e. iOS or Android. It is built in a specific programming language. While the native iOS apps are written in Objective-C or Swift, whereas the native Android apps are worked around with Java. These apps provide a high degree of reliability and quick performance.

Good Read: Native Mobile Apps - Are They Really Better Than Web Apps?

2. Web app

In contrast to computer-based software applications that run locally on the device's operating system, a web application is application software that runs on a web server. A web browser with an active network connection is used by the user to access web applications. 

3. Hybrid app

A hybrid app is a software that includes characteristics of both native and online apps. The problem with hybrid applications is that their pace is dependent on the browser's speed; hence, hybrid mobile apps are typically slower than native apps.

4. Progressive web app

A progressive web application (PWA) is a sort of web-based application software constructed with common web technologies such as HTML, CSS, and JavaScript. The design of these apps will help them to run on any platform that supports standards-compliant browsers, including desktop and mobile devices. 

General Mobile App Security Principles

General Mobile App Security Principles

One must perform mobile application security testing all through the development process till the application is released. Various types of testing are carried out, and given below are some of them.

1. Black-box testing

Black Box Testing is a software testing technique that tests the functionality of application software without knowing the internal code structure, operational characteristics, or internal routes. It is also referred to as Behavioral Testing or Zero-Knowledge Testing. 

2. White-box testing

White Box Testing is a software testing method in which the underlying structure, layout, and code of the software are examined to ensure that the input-output flow is correct and to improve design, usability, and security. It is also known as clear box testing or Full Knowledge Testing.

3. Gray box testing

Grey box testing is a software testing approach used to test a software product or application with just a limited understanding of the application's internal structure. The goal of gray box testing is to look for and detect faults caused by poor code structure or application use.

4. Vulnerability testing

Vulnerability testing or vulnerability assessment is the practice of assessing security risks in software systems to reduce the likelihood of threats. The goal of vulnerability testing is to reduce the likelihood of hackers gaining unauthorized access to systems. 

It includes scanning networks, systems, and other parts of the ecosystem. Network and wireless assessment, host assessment, database assessment, and application scans are a few types of vulnerability assessments. 

5. Penetration testing

A penetration test, often known as a pen test, is an attempt to evaluate the security of software by exploiting its weaknesses in a safe manner. Human-based penetration testing is a manual process that is executed by human beings having special skill sets. 

While different tools are used in this process, human ingenuity is applied to exploit vulnerabilities and test for any attack. You will get all the necessary details of these testing methods in the OWASP Mobile Security Testing Guide.

Best Practices for Mobile App Security

Information is power. With such sensitive information at stake, mobile app developers must do everything possible to protect their users. Here are some ideas for how developers might include security in their apps:

  • Keep your code's security in mind at all times and strengthen it to make it difficult to break.
  • You must encrypt every piece of data transferred via your app.
  • Follow the idea of the least privilege which states that a program should be run with just the minimum required permissions.
  • It is critical to stay up to pace with the latest security algorithms and to adopt modern encryption methods whenever possible.
  • Many mobile applications use a client-server approach. It is critical to have security measures in place to protect backend systems against malicious attacks.

Well Read: 5 Mobile App Security Best Practices That Companies Need To Know

Strategy for Security Testing

Security testing, like functionality and requirement testing, necessitates an in-depth understanding of the app as well as a well-defined plan for carrying out the actual testing. Given below are a few strategies for security testing, which you will get in the detail in the OWASP Mobile Security Testing Guide.

1. Nature of the app

You have to decide how much security testing is necessary based on the type and purpose of your app. For instance, if it deals with financial transactions, you have to check payment gateways and add a multi-factor or two-factor authentication. To add an extra layer of security, a fingerprint or password login needs to be authorized.

2. Time required for testing

You must evaluate how much time you can commit to security testing based on the total time allotted for testing. 

3. Efforts needed for testing

Security testing is more difficult than other sorts of testing because there are few project rules for it. Therefore, you and your team must define and agree with the testing requirements. 

4. Knowledge transfer

You might need extra time studying the code or tools to comprehend the app's security and related testing. Devote extra time for this knowledge transfer before making a final testing strategy. 


Recently, malware sites were discovered to be masked with SSL certificates. Bots have now been added to the mix, which means attacks will be faster, more complex, and much more difficult to identify and control. It’s high time to revisit traditional mobile data safety features, and OWASP Mobile Security Testing Guide will be a living and breathing encyclopedia for every mobile security tester. 

Ultimate Guide to OWASP Security Checks

Published on Nov 3, 2021
Harshit Agarwal
Written by Harshit Agarwal
Harshit Agarwal is the co-founder and CEO of Appknox, a mobile security suite that helps enterprises automate mobile security. Over the last decade, Harshit has worked with 500+ businesses ranging from top financial institutions to Fortune 100 companies, helping them enhance their security measures.
Beyond the tech world, Harshit loves adventure. When he's not busy making sure the digital realm is safe, he's out trekking and exploring new destinations.


Chat With Us

Using Other Product?

Switch to Appknox

2 Weeks Free Trial!

Get Started Now