[🐛] [Security Vulnerability] User Access Token Stored In Plain Text in Device Memory

[MateuszMatyska]

Issue

I have identified a critical security issue in the library: user access tokens are stored in plain text on the device’s file system, posing a significant risk if the device is compromised or accessed by unauthorized apps.

Details:

• Android: The library stores access tokens in:

/data/data/<application_name>/shared_prefs/com.google.firebase.auth.api.Store.[...].xml

These files contain sensitive tokens in clear text.

• iOS: The library stores access tokens in:

Library/Caches/<app_name>/Cache.db

Tokens are saved without encryption or obfuscation.

Security Impact:
Storing tokens in plain text allows any process or attacker with access to the device’s file system (rooted/jailbroken devices, backups, or certain debugging tools) to retrieve valid user tokens, potentially compromising user accounts and exposing sensitive data.

Suggested Solution:

• Store tokens securely using platform-provided secure storage mechanisms:

  • On Android: Use EncryptedSharedPreferences or the Android Keystore.

  • On iOS: Use the Keychain API.

• Ensure that sensitive data is never stored in plain text, even in caches or temporary files.

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Project Files

Javascript

Click To Expand

package.json:

# N/A

firebase.json for react-native-firebase v6:

# N/A

iOS

Click To Expand

ios/Podfile:

• I'm not using Pods
• I'm using Pods and my Podfile looks like:

# N/A

AppDelegate.m:

// N/A

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Android

Click To Expand

Have you converted to AndroidX?

• my application is an AndroidX application?
• I am using android/gradle.settings jetifier=true for Android compatibility?
• I am using the NPM package jetifier for react-native compatibility?

android/build.gradle:

// N/A

android/app/build.gradle:

// N/A

android/settings.gradle:

// N/A

MainApplication.java:

// N/A

AndroidManifest.xml:

<!-- N/A -->

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Environment

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react-native info output:

 OUTPUT GOES HERE

• Platform that you're experiencing the issue on:
  • [ x] iOS
  • [ x] Android
  • iOS but have not tested behavior on Android
  • Android but have not tested behavior on iOS
  • Both
• react-native-firebase version you're using that has this issue:
  • e.g. 5.4.3
• Firebase module(s) you're using that has the issue:
  • e.g. Instance ID
• Are you using TypeScript?
  • Y/N & VERSION

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