Security Implications of Mobile App Permissions: A Developer's Guide

How can developers responsibly and securely take advantage of permissions to improve their apps’ usability — without sacrificing user trust? On one hand, permissions allow your application to access the device's data or hardware, making the features you design functional and intuitive. Yet, when permissions are misused or over-requested, they can become a gateway to security risks, loss of user trust, and even regulatory compliance violations.

The functional role of permissions in mobile app development is undeniable. For example, if you’re developing a social media platform, camera and microphone access are important for users to record videos, take photos, or connect through video calls. Permissions like these make an app feel intuitive and fully integrated into the user’s life. Others, like location data for targeted advertising, serve business interests beyond functionality. In general, developers should exercise caution when using permissions that toe the line between usefulness and invasiveness.

Let’s explore some of the hidden risks of overarching permissions, along with mobile app security best practices any developer can use to mitigate these risks.

The hidden risks of overreaching mobile app permissions

While permissions may seem like technical necessities, their overuse can inadvertently expose users to privacy and security risks. One of the most prominent examples is the Facebook-Cambridge Analytic scandal, where a seemingly innocuous quiz app harvested massive amounts of user data that was sold and weaponized for political profiling. Another example is the 2020 controversy surrounding TikTok. By requesting permissions that included clipboard access, the app drew global scrutiny over its data practices, raising questions about how much access is too much.

Risks of specific mobile app permissions

Developers should be aware of the risks of specific types of permissions. For instance, location access can, if handled poorly, reveal a user's daily patterns or physical whereabouts. This misuse has the potential to expose users to stalking or surveillance. Permissions for cameras and microphones can also lead to alarming exposures if not properly managed. Imagine a malicious actor exploiting an app with unrestricted microphone access to eavesdrop on conversations or using a camera without consent to spy on users.

Similarly, contact access, which helps messaging or social networking apps function smoothly, has been misused to send spam or phishing messages to users’ entire address books. Permissions for SMS and call logs have historically been exploited to intercept two-factor authentication codes or trick users into subscribing to premium services. A prominent example of this technique is the Android malware Joker, which bad actors use to exploit SMS permissions to silently enroll users in premium services.

Risks of third-party SDKs

Beyond the permissions you explicitly design into your app, third-party SDKs integrated into your app can add another layer of risk. Many SDKs, such as those for analytics, advertising, or social login, introduce their own permissions or data collection practices. These SDKs may collect data beyond what is outlined in your app’s privacy policy, creating compliance risks and eroding user trust. For instance, an analytics SDK might gather location data even if your app doesn’t explicitly need it. Outdated or insecure SDKs can also create risks, leaving your app susceptible to attacks or unauthorized data access.

As a developer, it’s important to ask not only whether your app’s permissions are truly necessary for its core functionality but also whether third-party SDKs you include in your app might introduce unnecessary risks.

Mobile app security best practices to avoid permissions risks

To avoid these types of risks and more, developers play an important role in maintaining responsible permissions design and following mobile app security best practices. Here are a few ways to keep your apps compliant and your users safe:

• Adhere to the principle of least privilege: Only request permissions essential to your app’s functionality. For example, if you’re developing a photo editing app, it doesn’t need access to call logs or contacts to perform its core tasks.
• Implement granular permissions: Modern APIs now allow you to implement granular permissions, where requests are made incrementally and contextually. Instead of asking for every permission upfront, you can prompt users only when a feature requiring that permission is actively being used.
• Educate users: Provide in-app prompts, onboarding tutorials, and clear, concise privacy policies to educate users about why your app needs certain permissions.
• Use operating system tools: If you’re working with Android, the Google Play Console provides insights into permission usage over time. On iOS, privacy reports offer a way to analyze how your app accesses sensitive data.
• Audit and check permissions risks: Lint tools can identify unnecessary permissions in your code. Static analysis tools can also identify risks related to permissions.
• Improve your app’s overall security: Use the OWASP Mobile Security Testing Guide (MASTG) as a framework for assessing your app’s security. Third-party mobile app security testing tools like AppSweep from Guardsquare map closely to OWASP guidelines, reducing the overall risk of tampering and reverse engineering. In addition, a combination of code hardening, runtime application self-protection (RASP), and ongoing threat monitoring can keep your app secure throughout the entire development lifecycle.

The future of mobile app permissions and security

As privacy regulations like GDPR and CCPA become more stringent, app developers are under increasing pressure to design systems that prioritize user privacy. These regulations emphasize data minimization, requiring apps to collect only the information they absolutely need to function. Non-compliance can lead to steep fines, but more importantly, it can erode user trust and damage your brand reputation.

Looking to the future, trends such as adaptive permissions and privacy dashboards are also emerging as best practices. Adaptive permissions dynamically adjust based on user behavior, offering a more tailored and secure experience. Privacy dashboards, now commonplace on both Android and iOS, provide real-time insights into how permissions are being used, empowering users and developers alike to make informed decisions.

Zero-permission apps are also gaining traction. These rely on secure APIs to access data without requiring direct permissions from users, reducing the risk of misuse. Decentralized data storage is another innovative approach, keeping sensitive user information out of app ecosystems entirely.

Regardless of the approach you choose to adopt, the permissions your app requests should be carefully considered, transparently explained and securely managed. In addition, by improving your app’s overall risk of reverse-engineering or tampering, you can create trustworthy apps that users love.

Ultimately, responsible and secure design isn’t just about compliance—it’s about building a foundation of trust with your users. In a world where privacy concerns run rampant, your app can stand out from the competition by demonstrating that end-to-end security is a core value.

Want to learn more about preventing mobile app security risks? Get the report: Assessing Mobile App Security