Unauthorized access to files - APK Content Provider
Need
Prevent unauthorized access to files exposed through Content Providers
Context
• Usage of Android development for mobile applications
• Ensuring secure access controls in Content Providers
Description
1. Non compliant code
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.app">
<application
android:allowBackup="true"
android:theme="@style/AppTheme">
android:name=".InsecureContentProvider"...The above `AndroidManifest.xml` configuration defines a `ContentProvider` that exposes application data **without proper access restrictions**. - The attribute `android:exported="true"` allows any app on the device to access this Content Provider. - The `android:grantUriPermissions="true"` attribute permits other apps to access sensitive files without additional restrictions. - Without proper `android:permission` or `android:readPermission` attributes, any application can query and retrieve sensitive data. If an attacker or a malicious app exploits this misconfiguration, they can access or modify sensitive files without authorization.
2. Steps
• Open the `AndroidManifest.xml` file.
• Identify any `<provider>` components.
• Set `android:exported="false"` unless external access is explicitly required.
• If external access is necessary, enforce permission controls using `android:permission`.
• Avoid using `android:grantUriPermissions="true"` unless strictly needed.
3. Secure code example
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.app">
<application
android:allowBackup="true"
android:theme="@style/AppTheme">
android:name=".SecureContentProvider"...The secure version restricts access to the Content Provider by: - Setting `android:exported="false"` to **prevent external access**. - Using `android:permission="com.example.app.SECURE_PERMISSION"` to enforce authentication and limit access to trusted applications. - Explicitly defining `android:grantUriPermissions="false"` unless required. These changes ensure that only authorized apps with explicit permissions can access the files exposed by this Content Provider.