Mobile App Security Best Practices [2025]

6. Lack of Regular Updates

This is an ongoing process. It is crucial for a development agency or developers to regularly update the app they develop. Underlying technologies in mobile apps evolve due to security concerns and performance enhancement. And outdated files are often on hackers' radar to get unauthorized access to. If an app doesn't receive updates, it can pose security risks and be an easy target for attackers.

Regular updates allow developers to close security gaps, fix bugs, and improve performance.

When updates are not regularly pushed to users, any newly discovered weaknesses are left unaddressed, and hackers can exploit them. This is why outdated apps, which haven't been updated with the latest security patches, are more prone to cyber-attacks.

Updates also ensure that an app stays compatible with the latest operating systems and security standards. For instance, when a new version of Android or iOS is released, it may come with security improvements or new features that the app needs to integrate with to function properly and securely. If the app isn't updated, it might fail to work correctly or even expose users to new threats that those operating systems aim to prevent.

7. Insufficient testing

A mobile app's security is only as strong as its testing strategy. Without proper testing, you will make the app vulnerable. Common gaps include inadequate penetration testing, failure to scan for known vulnerabilities, and a lack of real-world attack simulations.

Integrate automated security testing into their CI/CD pipelines, conduct thorough vulnerability assessments, and regularly perform penetration testing.

Tools like SAST, DAST, and IAST can help identify weaknesses before attackers do. By prioritizing security testing throughout development, teams can minimize risks and build more resilient applications.

8. Improper session handling 

When you use a mobile app, it often remembers who you are after you log in. This is done through called a "session." If these sessions aren't managed correctly, it can lead to security problems. For example, if an app doesn't end your session when you log out, someone else might be able to continue using your account. Also, if the app doesn't have a timeout feature to log you out after a period of inactivity, anyone who picks up your device could access your account. Attackers can exploit these properties to gain unauthorized access.

To avoid these problems, handle the session correctly. Provide a server-side mechanism for closing sessions when the user logs out. Use appropriate timeout periods. Additionally, it generates session tokens, so it is resistant to guessing attacks.  By properly handling sessions, developers can protect the users' information and maintain the trust users have in applications.

Mobile App Security Best Practices

There are so many methods and practices you can employ, such as following Fort Knox for your mobile app. Let's take a look at some popular security practices that you should include when developing a mobile app. 

1. Prioritize Code Security

When developing a mobile app, writing secure code should be your priority. Your code is the backbone of your app. If malicious actors are able to reverse-engineer your code, they could potentially identify vulnerabilities, inject malicious code, or steal sensitive data.

There are some techniques that you can use against reverse engineering, tampering, and other forms of attack.

Obfuscation is a technique that converts code into a less readable form. This way, you make it more difficult for someone to reverse-engineer your app, even if they have access to the source code. Java and Kotlin help you obfuscate code.

Advanced encryption algorithms like AES (Advanced Encryption Standard) are used to encrypt code and data. You can use runtime protection tools that detect tampering with the app's code during execution and can trigger alerts.

2. Be Mindful of Third-Party Libraries

Third-party libraries can reduce development efforts. However, they can also introduce security risks. For attackers, third-party APIs have long been a prime target. There can be several risks in using third-party libraries, as follows;

If a library has a known vulnerability, attackers can exploit these weaknesses to compromise your app. Third-party libraries obtained from untrusted sources may contain malicious code.

Here are some practices to secure the app from third-party library risks.

• Before using a library in your app, review its code, check for vulnerabilities, and cross-check if it's from a reliable source.

• Just as your app needs regular updates, so do the third-party libraries it uses.

• Use Libraries from sources such as GitHub, official app stores, or reputable developer communities.

• Use package managers like CocoaPods for iOS or Gradle for Android.

By being cautious with third-party libraries, you can avoid introducing unnecessary vulnerabilities into your app.

3. Enhance authentication

Authentication system should be strong within your app. There are several ways to make the authentication mechanism strong. Multi-factor authentication (MFA) is one of the popular ways to enhance authentication. There are so many MFA services available today, such as Google Authenticator or SMS-based one-time passwords (OTPs).

Plus, biometric authentication is a user-friendly way to authenticate users. On iOS and Android, you can use the Face ID and fingerprint scanner. Plus, enforce rules of minimum password length and a mix of characters. This makes it harder for attackers to gain unauthorized access through brute force or guessing.

Enforce password strength policies that require users to use at least one uppercase letter, one lowercase letter, one special character, and a number.

4. Minimize Data Storage on Devices

We don't recommend that you store sensitive data on mobile devices. It increases the data theft risk. It's excellent practice to limit the data you store locally on devices. There are so many disadvantages to it. For example, if sensitive data such as passwords, credit card details, or personal information is stored on the device and the device is compromised, it can easily be accessed by attackers.

Here's what you can do to protect sensitive data on mobile devices.

Don't store sensitive data on the device. Instead, use secure cloud storage or backend servers with strong encryption. Cached sensitive information temporarily when necessary and encrypted before storing it on the device. You Store user credentials and sensitive transaction data on secure servers with encryption in transit (HTTPS) and at rest.

If data must be stored locally on the device, use the encryption method. Use Keychain (iOS) or Keystore (Android) to store login tokens or session IDs.

Implement data retention policies that ensure sensitive information is only stored for as long as absolutely necessary. Periodically delete or anonymize old or unused data. For example, you can build a mechanism that automatically purges stored user session data or sensitive information after a certain period of inactivity.

5. Secure All Communication Channels

In mobile app development, communication between the app and external services must be secure; for example, APIs or servers. To secure your app's communication, you should use HTTPS (SSL/TLS), which is a secure communication protocol that encrypts data in transit and prevents man-in-the-middle attacks.

Make sure all API calls from your app use HTTPS rather than HTTP, even when communicating with local or development servers. If you need to transmit sensitive information, ensure that it is encrypted using strong algorithms before transmission.

Use RSA to encrypt messages or AES to encrypt data before it's transmitted over a network. You may have heard of certificate pinning when the server certificate is hardcoded in your app. With this, the app only communicates with trusted servers. Implement certificate pinning in your app to ensure it only connects to your backend servers and prevents attackers from redirecting traffic to malicious servers.

6. Conduct Regular Security Testing

Regular security testing is the best way to find out potential vulnerabilities. By proactively testing your app, you can reduce the likelihood of a security breach. Here's how to conduct thorough security testing for your mobile app:

You can use automated security scannerside to identify vulnerabilities such as SQL injection, cross-site scripting (XSS), and insecure data storage. There are so many tools like OWASP ZAP or Checkmarx that can automatically scan your app for vulnerabilities.

We always recommend you perform manual penetration testing. Automated tools are not that effective. Instead of solely relying on tool-based automated testing, combine manual and automated testing to thoroughly test your app faster. You can hire a certified mobile app tester to perform penetration testing and assess your app's overall security.

6.1. Test for Compatibility with Security Best Practices

Ensure your app follows best practices by performing tests that check for the use of secure coding standards, correct error handling, proper data encryption, and strong authentication mechanisms. For example; test your app to ensure that sensitive information is never stored in plain text and that all sensitive transactions are encrypted.

7. Ensure Secure API Integration

APIs (Application Programming Interfaces) allow your app to interact with external services, but they can also be vulnerable to attacks. If APIs are not properly secured, they can provide a gateway for attackers to access sensitive data or manipulate app behavior.

In addition, the APIs may provide an easy path around the user authentication implemented in the app so that attackers can directly access sensitive data. Injection attacks that include SQL injection can completely compromise an app if not properly validated.

To secure your APIs, use OAuth 2.0, JWT (JSON Web Tokens), or API keys. Role-based access control (RBAC) should also be used. Validate all input to the API and sanitize user-generated content. Reject requests that contain invalid or malicious data. It will prevent your app from injection attacks. You can use whitelisting for inputs.

Don't forget to use tools to monitor API traffic and search for unusual usage patterns; spikes in traffic or repeated failed requests could suggest a brute-force or DoS (Denial of Service) attack.

Implement rate-limiting on your APIs to make abuse harder and reduce the chances of DoS attacks.

8. Implement Access Controls

Access control is essential to ensure that users or systems can only access the resources they are authorized to. This prevents unauthorized access to sensitive data and functionalities within your app. Without strict access controls, users may be able to access data that isn't relevant to them. To ensure that only authorized users can access certain parts of your app, consider these approaches:

8.1. Role-Based Access Control (RBAC)

With RBAC, you can assign different roles (e.g., user, admin, guest) to users and define permissions based on those roles. This limits access to sensitive data or functionality to only those who need it.

A regular user might only have access to their account settings and view data, while an admin could manage user permissions and data and perform system maintenance.

8.2. Use Fine-Grained Permissions

In addition to RBAC, ensure that access to specific data is controlled. For example, users should only be able to view their own data and not others' personal or sensitive information.

Example: For a social media app, implement access controls to ensure users can only see and edit their profiles, posts, and messages.

8.3. Principle of Least Privilege (PoLP)

Grant users and systems the minimum level of access needed for them to perform their tasks. This minimizes the risk of unauthorized actions.

Example: Ensure that API keys or service accounts used by your app's backend systems have access to only the necessary resources, not to everything within your infrastructure.

9. Encrypt Sensitive Data

Encryption is one of the best methods to secure sensitive data. Data in transit or at rest must be encrypted. Algorithms like AES-256 are popularly used for encryption. Follow the rule that data should never be stored in plaintext. Encrypt passwords, payment information, and personal details.

10. Ensure Proper Session Handling

Session management is critical for user authentication. Proper session handling ensures that users' sessions are protected and cannot be hijacked or tampered with.

If session tokens are not protected, attackers could hijack a session and impersonate legitimate users. Beyond this, insecure session handling could allow attackers to fix a session ID. Follow these best practices:

Use session tokens, e.g., JWT or session IDs. They are long and random.

Ensure that these tokens are transmitted securely over HTTPS and are stored in secure places, such as HTTP-only cookies. Plus, session tokens are stored in HTTP-only cookies to prevent JavaScript-based attacks like cross-site scripting (XSS).

You can reduce the risk of session hijacking with an automatic session timeout feature. It will trigger after a specified period of inactivity. Here's how you can build it. Set an expiration time for session tokens. Trigger it after 30 minutes of inactivity. If this is enabled, the user will need to log in again after 30 minutes if he/she remains inactive.

Combine session management and multi-factor authentication. When you have combined session management with MFA, Even if a session token is compromised, MFA can help ensure that the attacker cannot access the app.

Outsource Security for Better Protection

It can be overwhelming to keep up with all the evolving threats and technical complexities. That's where you can use managed security services. These services take the weight off your shoulders by providing expert security monitoring, threat detection, and even compliance support. Basically, instead of trying to handle everything in-house, you let the pros keep an eye on things 24/7.

For mobile applications, you are in touch with Brilworks. We acknowledge that user information should be strictly kept confidential and secure, however time-consuming and involved. That's why we instill top-of-the-line security practices into all of our mobile apps from inception. Whether through secure communication methods, data encryption, or just general vulnerability scanning, we strive to ensure apps that are put on the front line are completely safe.

Outsourcing security to experts means you don't have to worry about handling it all yourself. You can focus on building your app, knowing that experts are keeping it safe from hackers. Plus, with the cloud now a big part of mobile development, managed services ensure that everything from data storage to app performance stays secure in an ever-changing environment.

We are proud of the secure, scalable mobile solutions we deliver here at Brilworks that fit today's business needs. Whether launching an app or scaling up, you get the benefit of extensive security knowledge and our promise of bringing to market tech that is innovative as well as safe when a business partners with us.

Final Words

As a mobile application development company, it is important that comprehensive security measures are integrated into the app development lifecycle. It is through the implementation of strong security protocols that it is possible to protect both your app and its users from these cyber threats. Thus, such an approach ensures fewer chances of data breaches, as well as vulnerabilities that could compromise the integrity of your app and the users' information in general.

Secure your code first. Techniques like encryption, encoding, and code obfuscation make it much more difficult for an attacker to reverse-engineer or tamper with your app. Another thing is the use of third-party libraries with caution. Even trusted libraries may introduce vulnerabilities into your application. Regular updates and thorough security analysis of such libraries ensure that your app is well protected against risks.

Authentication is another critical area that requires strengthening. Multi-factor authentication (MFA) and advanced security measures ensure that only legitimate users can access sensitive features of your app. Regularly patching your app to address vulnerabilities is equally important, as security threats evolve over time, and keeping your app up to date minimizes the risk of attacks.

Data storage on both the device and in the cloud must also be secured to protect user information. Encrypted databases and secure APIs help keep sensitive data out of unauthorized access. Secure communication protocols such as SSL/TLS ensure the encryption of data in transit. This is impossible for an attacker to execute man-in-the-middle attacks. In addition, a logging and monitoring system would offer real-time detection of suspicious activities, thereby alerting response for potential threats in time. Securing every aspect, from development to deployment, will protect your app and establish users' confidence.