How to Safeguard Your Mobile App Against API Security Threats

How to Safeguard Your Mobile App Against API Security Threats  

Mobile applications are becoming an integral part of our everyday activities, offering entertainment, productivity, and convenience. These apps strongly rely on Application Programming Interface (APIs) for communicating with servers and retrieving data from them.

Even though mobile apps strongly rely on APIs for communication with other third-party APIs and back-end systems, they also create security risks that need to be addressed to prevent data breaches and other cyber attacks. In this article, we will dive deeper into learning more about the top security practices you can follow to protect your mobile app from API security threats.

2 Security Practices to Prevent API Attacks 

Discover 12 essential security practices designed to safeguard your APIs from potential attacks. This guide outlines key measures to enhance your API security, ensuring robust protection against unauthorized access and threats.

1.  Mitigate Broken Object Level Authorization (BOLA)    

BOLA occurs when an online attacker manipulates an object reference by gaining access to unauthorized data. A common manipulation method would be changing the ID parameter value within a URL to access someone’s account. You can mitigate BOLA in the following ways:

  • Only grant access to authorized users for accessing specific data.
  • Use token-based authentication based on users’ roles.
  • Test your authorization mechanisms for any vulnerabilities.

Regular security testing and implementing proper access controls are the only ways to mitigate BOLA.

2. Use the Google Consent mode to comply with data privacy regulators

During the global pandemic, Google managed to release its Consent Mode, which has taken data privacy a step forward in securing valuable data for marketing purposes. They recently launched their updated Google Consent Mode v2, which has introduced two additional tag settings:

  • Ad_user_data: Controls whether personal data is sent to the Google service or not.
  • Ad_personalization: Controls and checks if you can use the data you’ve collected for ad personalization (remarketing).

The Google Consent Mode tag manages how Google Ads cookies will behave based on user consent. If the user gives consent for ad cookies, Google Ads will allow you to collect full data for advertising purposes.

In case the opposite happens where the user doesn’t give consent, Google Ads won’t use their data for advertising purposes.

Data privacy regulators like the General Data Protection Regulation (GDPR) require organizations to ensure safe transfer and grant users complete control over their data, especially through APIs.

API security considerations include:

  • Data encryption
  • Authorize and authenticate API users
  • Providing mechanisms for data portability

Failing to comply with the standards of data privacy regulations can result in large fines, penalties, and a tarnished reputation.

3. Prevent API reverse engineering   

Before API abuse, online attackers need to first discover it and understand its calling structure and capabilities. API reverse engineering can be prevented only when a developer makes it challenging for an online attacker to learn more about the application and prevent observation of active API calls.

In order to make this possible, and learn more about how to prevent API attacks, follow these tips:

  • Use anti-tamper techniques to block manipulated apps from running
  • Persistent data always should be written for secure storage
  • Use device rooting, debugger, and instrumentation frameworks

Even though online attackers can fake trusted certificates to their devices and manipulate API calls by using man-in-the-middle attacks, you can use certificate pinning to strengthen communication security against these consistent threats.

4. Encrypt your data using HTTPS

One of the most effective techniques on how you can keep your mobile app secure is by encrypting your data. This is a fundamental part of API security and prevents man-in-the-middle (MitM) attacks.

Data encryption involves converting your data into a code that can only be used by authorized users. Even if a breach were to happen, the attacker wouldn’t be able to read the data since they have no authorized capabilities.

Data should be encrypted both in transit and at rest. Depending on what your application requires, you can encrypt your data through SSL, AES, or RSA.

5. API rate limiting   

Without rate limiting, APIs are easily abused, which creates more space for online attackers to use denial of service (DoS) attacks or unauthorized data scraping. Online attackers can make a large number of requests to the API in only a short period of time, causing the server to slow down significantly or even crash.

That’s why API rate limiting is important, and here’s what you can do to prevent these types of attacks:

  • Use rate limiting based on IP addresses or user roles.
  • Use tools for API rate limiting.
  • Monitor and adjust the rate limit based on your traffic patterns.

In case some exceed the rate limit, the API will stop responding to requests and return an error code.

6. Input validation   

User inputs need to always be validated to prevent SQL injections, Cross-site scripting, and any other injection attacks. Web Application Firewalls (WAFs) are excellent for filtering out malicious requests.

Input validation is an important security measure that is used for preventing common injection attacks that include SQL injections, Cross-Site Scripting (XSS), and Command Injection. Input validation verifies information entering the system, making it much harder for online attackers to become successful in completing their attack.

Input validation is used as a first-line defense mechanism, preventing any malicious data from entering your system. It safeguards the accuracy and integrity of your data, making sure that only trustworthy information is accepted. If there’s no proper validation, the wrong data can be entered and crash your application.  

7. Secure mobile app storage

Secure mobile app storage is an important part of secure coding. All developers need to make sure that sensitive information is securely stored using the latest encryption algorithms.

Storing sensitive information locally on a user’s device is a security risk, but this can be done either through Android’s Keystore, or iOS’s Keychain for protecting sensitive data like tokens, API keys, and other important credentials.

Both iOS’s keychain and Android Keystore provide secure locations for you to store your sensitive data on the device.

8. Token-based authentication mechanisms  

Token-based authentication is a popular mechanism for user authentication in mobile applications. Developers will usually use OAuth2, or JSON Web Tokens (JWT). OAuth2 enables users to grant access to third-party applications without having to share their credentials.

This method is mostly used for protecting important credentials of the user such as their email/password from being reused or reverse engineers during a data breach.

9. Multi-factor authentication

Multi-factor authentication (2FA) is used for improving mobile app security. 2FA requires two or more forms of identification. However, 2FA needs to be optimized for mobile app levels, and not contain any weak identification mechanisms. 2FA can block 100% automated bots, 96% of phishing attacks, and 76% of all targeted attacks.

At the mobile level, 2FA is best when verification is done through the use of a fingerprint or PIN to grant access to the application’s most sensitive areas. This extra level of security makes it much more challenging for online attackers to gain access to your mobile applications.

10. Implement proper error handling   

Proper error handling is an important part of secure code development. Mobile developers need to be ready to handle errors in a way that doesn’t compromise the application’s security. Error messages should never reveal sensitive information, or the cause of the error unless it’s something that the user can act on or needs to be informed about.

Error messages need to always be logged securely, never reveal sensitive information, and should never be displayed to end-users.

 11. Conduct regular code reviews    

Regular code reviews should always be conducted and are an important part of successful code development. Code reviews help you address security issues before your mobile app is released. It’s better to address these issues during the development phase than after the application is released.

After you are done with the work, it’s always a good idea to have someone make sure that all codes are reviewed and see if they are all correct. It’s always best to have someone on your team who can view your code as if they were an attacker themselves. This helps you become more prepared when you get to experience it in a real-case scenario.

12. Keep everything updated  

Don’t forget to stay up to date with security patches and update the software and libraries that you use in your API. API security for mobile applications is a challenge that developers always face and needs to be carefully planned, implemented, and monitored.

Keeping your mobile apps secure is never a one-time process, but requires continuous updates to your software, security patches, and practices. There are always new methods that online attackers try to use to take over sensitive information and harm mobile applications, but don’t let that stop you from updating your security practices.


Adopting robust security practices is essential for protecting your mobile app from API threats. Implementing and regularly updating these measures will help safeguard sensitive data and enhance user trust. Stay vigilant and proactive in your security efforts to keep pace with evolving cyber threats and maintain a secure app environment.