How to Perform Mobile App Security Testing Step-by-Step

A 2025 report shows that people collectively spent around 4.2 trillion hours of their time on mobile apps. This isn’t surprising as we use these apps for almost everything, from managing finances and tracking health to booking flights and even ordering groceries.

But this convenience comes with a responsibility. Mobile apps regularly work with user information to offer tailored services and improve experiences. And a lot of the information these apps use is confidential in nature, like login details and financial records.

Threat actors are constantly on the lookout for security gaps in mobile apps, which they can exploit to gain access to user accounts and spread malware, steal data, and cause financial fraud. This is why robust mobile app security testing is a must.

In this blog, we will guide you through the basics of mobile app security testing, including its types and techniques, as well as best practices for optimization.

TL;DR

• Mobile app security testing helps you detect and fix vulnerabilities like poor authentication, improper session management, and excessive permissions
• Common mobile app security risks include malware attacks, code tampering, insecure communication, and data leakage
• Different mobile application security testing techniques are vulnerability scanning, risk assessment, penetration testing, SAST, DAST, and IAST
• For secure mobile app development, focus on strong data encryption, secure coding practices, authentication and authorization, and third-party library management
• To optimize mobile application security testing, secure your source code, use an API security framework, and implement code obfuscation
• What Is Mobile Application Security Testing and Why Does It Matter
• Mobile application security testing examines an app’s defenses to identify weaknesses that may lead to data exposure, functional failures, or integrity risks.

Why is mobile application security testing important?

Because it helps to:

Protect confidential user information (e.g., customer PII, financial records, login credentials) from leaks or unauthorized access
Reduce risks of third-party libraries, SDKs, and APIs
Detect issues before deployment, which helps you reduce the cost of fixes
Ensure compliance with regulatory standards like PCI-DSS and ISO 27001
The goal is to prevent exposure by testing mobile applications for security vulnerabilities before attackers find them.

What Are the Common Security Vulnerabilities in Mobile Apps?

Before we talk about the different ways of mobile app security posture assessment methods, take a look at the security threats you might encounter:

1. Malware attacks: This happens when attackers inject malicious software into your apps for the purpose of stealing data or spying on user accounts. Malware attacks can even happen when sessions are not invalidated after a logout, which allows attackers to take over active sessions and get access to user accounts.

2. Insecure communication: Without strong encryption and outdated security protocols, data transfers between your mobile app and server can be intercepted by hackers via techniques like man-in-the-middle attacks. Risks increase even more if your apps use plaintext HTTP, weak TLS versions, or fail to check SSL certificates.

3. Weak authentication: If your mobile app’s login workflow depends on simple passwords, lacks multi-factor authentication, and doesn’t enforce any strong credential policies, it can leave security gaps that can make the app vulnerable to brute-force attacks. Weak authentication can affect user accounts as well as your backend databases.

4. Code tampering: Here, attackers modify your app’s source code or binaries to alter its behavior or bypass security controls. After the attackers manipulate your app, they can easily steal confidential data, disable security checks, and even redirect your users to malicious services.

5. Data leakage: Insecure data storage, poor encryption, or incorrect data handling can make sensitive information such as login passwords, tokens for authentication, or personal details vulnerable to security threats like identity theft, account takeover, and phishing.

A Close Look at Mobile Application Security Testing Types and Techniques

Here are the most commonly used mobile application vulnerability testing methods and techniques:

1. Vulnerability scanning

This is an automated mobile app vulnerability assessment technique that scans your app’s code and dependencies against a database of known vulnerabilities, such as the Common Vulnerabilities and Exposures (CVE) system, to find problems like outdated libraries and weak authentication.

Execution tips

• Scan both your app code and backend API with automated scanners like MobSF or AppScan
• Review detected issues and prioritize them based on severity
• Scan again after fixes to confirm issues are resolved

2. Penetration testing

Penetration testing is not like automated scans; you mainly perform it manually. You simulate real-world attacks to find deeper issues in your app’s authentication, session management, and business logic.

Execution tips

• Perform reconnaissance to map your app’s architecture, APIs, and data flows
• Manually exploit vulnerabilities (SQL injection, access control gaps)to verify their real impact
• Document all your findings along with risk ratings and recommendations on how to fix them

3. Risk assessment

Risk assessment is a type of mobile security assessment that helps you plan what to fix first. It assesses the impact of a potential security threat on your app by considering aspects such as the sensitivity of the data, the effects of a breach, and the attack vectors.

You can use threat modeling along with risk assessment to identify critical assets and understand attack paths.

Execution tips

• First, determine assets, entry points, and high-value data flows
• Use threat modeling methods like STRIDE to find threats
• Assign an impact score to each threat and prioritize resolution based on that

4. Fuzz testing

The main idea of fuzz testing is to feed invalid, unexpected, and random inputs to your app to see how it handles this malformed data, whether it crashes or not, and uncover problems such as buffer overflows and memory leaks.

Execution tips

• Start with identifying input points like forms, file handlers, and search fields
• Feed random or malformed input to your app with tools like LibFuzzer or Peach Fuzzer
• Closely examine crashes, logs, and stack traces to find edge cases

5. Static Application Security Testing (SAST)

SAST works well as early-stage mobile application vulnerability testing.

In SAST, you assess your app’s source code, bytecode, or binaries without actually executing the code. This helps you detect insecure API calls, hardcoded secrets, and risky data handling patterns before issues reach production.

Execution tips

• Integrate SAST testing into your CI/CD pipeline to catch issues early in the development cycle
• Run static scans, review flagged issues, and feed results back to developers so they can address issues while they code
• Run scans again to verify if issues are resolved

6. Dynamic Application Security Testing (DAST)

DAST tests your mobile app when it’s running by mainly focusing on runtime behavior, network communication, and user inputs to uncover issues such as broken authentication and insecure data transmission. DAST is done to check the issues your app might face in real-world conditions.

Execution tips

• First, deploy your app in a controlled environment or on real devices
• Simulate attacks on input fields, APIs, and backend interactions
• Monitor server responses, error messages, and logs to detect unvalidated input or information leakage

7. Interactive Application Security Testing (IAST)

IAST combines elements of SAST and DAST for testing mobile applications for security vulnerabilities. IAST tools use agents or sensors to observe code execution and data flows, and help you identify vulnerable third-party libraries, XSS, and insecure configurations.

Execution tips

• Integrate the IAST agent into your app’s runtime before you execute functional or automated tests
• Make sure the IAST sensor is monitoring the critical modules and workflows
• Watch the findings in real time and check for data handling errors, authentication flaws, and injection points

Core Principles of Secure Mobile App Development

If you want to build mobile apps that are safe and reliable, you must infuse security at every stage of your development workflow.

Here are some principles you can follow to ensure a secure software development lifecycle (SDLC):

1. Secure coding practices

Writing code with security in mind helps you prevent risks of SQL injection, buffer overflows, and cross-site scripting, and ensures your app can withstand threats throughout the development cycle.

So, how do you implement secure coding practices?

• Check and sanitize all user inputs, such as file uploads, names, and search queries
• Use strong passwords, multi-factor authentication, and strict access controls
• Adopt proper error and exception handling; keep details like stack traces, class names, and query errors securely in server-side logs
• Automate code reviews to flag errors and vulnerabilities faster
• Apply least privilege access in code components to ensure users and systems have access to only the resources that are necessary to operate

2. Strong data encryption

Robust encryption ensures that even if your app’s data or server is compromised, attackers cannot read or misuse it. Therefore, you must encrypt data both at rest and in transit, as well as data stored on devices or servers.

3. Authentication and authorization

This helps you ensure that only authorized users access the apps and only perform actions they are allowed to. For this, you should enforce stringent password policies and secure session management.

Plus, you must handle authorization on the server side to block users from manipulating permissions on the client side.

4. Third-party library management

Third-party libraries and frameworks are lifesavers for speeding development, but they come with external code that you cannot control. And poorly managed or outdated libraries can have insecure APIs, hidden malware, and other supply chain vulnerabilities.

Therefore, you must regularly audit and update libraries and pin dependencies to specific versions to stop untested updates from reaching production.

5. Regular updates

If your code and dependencies are outdated, they can quickly turn into entry points for threat actors. So make sure you frequently update logic, security patches, framework versions, and SDKs.

Challenges You Might Face During Mobile App Security Testing

Here are the challenges you might encounter when performing mobile app security testing, along with solutions to help you navigate them.

Challenge	Description	How to Overcome
Platform and device fragmentation	Mobile apps run on multiple devices and operating systems, making it hard to execute security tests on every version and configuration.	While testing every device setup might not be possible, focus on OS versions and mobile models that users use the most.
Difficulty sourcing DAST tools	Not many DAST tools are specifically designed for mobile application security testing; therefore, it’s challenging to find tools that simulate real-world mobile interactions.	Select mobile application security tools that support real-device scanning and combine DAST with other testing techniques like SAST and pentesting to improve coverage.
Language coverage	Many mobile app security testing tools don’t support every development language, which can be a barrier to writing test scripts.	Look for mobile security testing tools that support languages your team is comfortable with and conduct manual code reviews to supplement testing.
Defaulting to simulated tests	Teams use emulators and simulators for mobile application security testing because it’s easier, but these don’t always reflect actual security risks.	Perform security testing on real devices and under realistic network and usage conditions to detect issues you can only find in production environments.

Best Practices That Make Your Mobile App Security Testing More Effective

These are some mobile app testing best practices to ensure both your testing processes and mobile app are reliable and secure.

1. Secure your source code

Protecting your app’s source code is important to defend against reverse engineering and code tampering. You can take the help of version control systems like Git to limit code access to only authorized developers and testers in your team.

2. Enable Runtime App Self-Protection (RASP)

RASP helps your app defend itself in real time by detecting and blocking suspicious behavior such as attempts to access sensitive data, while the app is running. RASP gives your app protection against runtime threats that traditional testing or firewalls might not be able to catch.

3. Implement code obfuscation

Code obfuscation is done to make your app’s source code hard for attackers to read, reverse engineer, or tamper with. For this, you transform logic, rename identifiers, hide APIs and algorithms, and insert dummy code.

4. Integrate an API security framework

Mobile apps usually rely on APIs to communicate with backend services, and therefore, it’s essential to protect these communication channels. To do this, you can implement input validation, authentication, and authorization mechanisms (OAuth 2.0, JWT), and rate limiting to stop denial-of-service attacks.

Secure Your Mobile Apps Testing with TestGrid

TestGrid is an AI-powered test automation platform that helps you automate your mobile app security testing, ensure better coverage, and catch issues before your users face them.

The platform’s real device cloud offers you a range of iOS and Android devices on which you can run security tests under real-world conditions. And with the codeless automation feature, you can create automated tests without the need for writing code.

TestGrid ensures all your data is encrypted both at rest and in transit using industry-standard protocols, and the platform applies the principle of least privilege so that only authorized personnel can access sensitive information.

If you’re operating in regulated industries, TestGrid helps you maintain security by keeping the test traffic, credentials, and sensitive data within your self-hosted infrastructure and supports security compliance with standards and frameworks such as GDPR, HIPAA, PCI-DSS, ISO 27001, and SOC 2.

Wrapping It Up

As the user base continues to grow, testing and protecting every feature, every interaction, and every bit of data exchanged through mobile apps becomes essential for maintaining and safeguarding user trust.

By now, you must have a fair idea about why mobile application security testing is so critical. To stay ahead of the increasing cyber threats and build secure mobile apps, understand the different risks thoroughly, apply the right testing techniques, and follow the best practices for the best results.

To ensure your mobile apps remain resilient against threats without slowing down development, start a free trial with TestGrid today, and automate your mobile app security testing at scale.

This blog is originally published at TestGrid