Fix insecure rules

Use this guide to understand common vulnerabilities in Cloud Firestore Security Rules configurations, review and better secure your own rules, and test your changes before deploying them.

If you receive an alert that your Cloud Firestore database isn't properly secured, you can resolve the vulnerabilities by modifying and testing your Cloud Firestore Security Rules.

To view your existing Security Rules, go to the Rules tab in the Firebase console.

Understand your Cloud Firestore Security Rules

Cloud Firestore Security Rules protect your data from malicious users. The default rules for any Cloud Firestore instance created in the Firebase console deny access to all users. To develop your app and access your database, you'll need to modify those rules and might consider granting blanket access to all users in a development environment. Before deploying your app to a production environment, however, take the time to properly configure your rules and secure your data.

As you're developing your app and testing different configurations for your rules, use the Cloud Firestore emulator to run your app in a local development environment.

Common scenarios with insecure rules

The Cloud Firestore Security Rules you might have set up by default or as you initially worked on developing your app with Cloud Firestore should be reviewed and updated before you deploy your app. Make sure you properly secure your users' data by avoiding the following common pitfalls.

Open access

As you set up Cloud Firestore, you might have set your rules to allow open access during development. You might think you're the only person using your app, but if you've deployed it, it's available on the internet. If you're not authenticating users and configuring security rules, then anyone who guesses your project ID can steal, modify, or delete the data.

Not recommended: Read and write access to all users.
// Allow read/write access to all users under any conditions
// Warning: **NEVER** use this rule set in production; it allows
// anyone to overwrite your entire database.

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if true;
    }
  }
}
Solution: Rules that restrict read and write access.

Build rules that make sense for your data hierarchy. One of the common solutions to this insecurity is user-based security with Firebase Authentication. Learn more about authenticating users with rules.

Content owner only

service cloud.firestore {
  match /databases/{database}/documents {
    // Allow only authenticated content owners access
    match /some_collection/{document} {
      allow read, write: if request.auth.uid == request.resource.data.author_uid
    }
  }
}
  

Mixed public and private access

service cloud.firestore {
  match /databases/{database}/documents {
    // Allow public read access, but only content owners can write
    match /some_collection/{document} {
      allow read: if true
      allow write: if request.auth.uid == request.resource.data.author_uid
    }
  }
}
  

Access for any authenticated user

Sometimes, Cloud Firestore Security Rules check that a user is logged in, but don't further restrict access based on that authentication. If one of your rules includes auth != null, confirm that you want any logged-in user to have access to the data.

Not recommended: Any logged-in user has read and write access to your entire database.
service cloud.firestore {
  match /databases/{database}/documents {
    match /some_collection/{document} {
      allow read, write: if request.auth.uid != null;
    }
  }
}
Solution: Narrow access using security conditions.

When you're checking for authentication, you might also want to use one of the authentication properties to further restrict access to specific users for specific data sets. Learn more about adding security conditions and role-based access.

Role-based access

service cloud.firestore {
  match /databases/{database}/documents {
    // Assign roles to all users and refine access based on user roles
    match /some_collection/{document} {
     allow read: if get(/databases/$(database)/documents/users/$(request.auth.uid)).data.role == "Reader"
     allow write: if get(/databases/$(database)/documents/users/$(request.auth.uid)).data.role == "Writer"

     // Note: Checking for roles in your database using `get` (as in the code
     // above) or `exists` carry standard charges for read operations.
    }
  }
}

Attribute-based access

// Give each user in your database a particular attribute
// and set it to true/false
// Then, use that attribute to grant access to subsets of data
// For example, an "admin" attribute set
// to "true" grants write access to data

service cloud.firestore {
  match /databases/{database}/documents {
    match /collection/{document} {
      allow write: if get(/databases/$(database)/documents/users/$(request.auth.uid)).data.admin == true;
      allow read: true;
    }
  }
}
  

Mixed public and private access

service cloud.firestore {
  match /databases/{database}/documents {
    // Allow public read access, but only content owners can write
    match /some_collection/{document} {
      allow read: if true
      allow write: if request.auth.uid == request.resource.data.author_uid
    }
  }
}
  

Closed access

While you're developing your app, another common approach is to keep your data locked down. Typically, this means you've closed off read and write access to all users, as follows:

// Deny read/write access to all users under any conditions
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if false;
    }
  }
}

The Firebase Admin SDKs and Cloud Functions can still access your database. Use these rules when you intend to use Cloud Firestore as a server-only backend in conjunction with the Firebase Admin SDK. While it is secure, you should test that your app's clients can properly retrieve data.

Learn more about Cloud Firestore Security Rules and how they work in Get Started with Cloud Firestore Security Rules.

Test your Cloud Firestore Security Rules

To check your app's behavior and verify your Cloud Firestore Security Rules configurations, use the Cloud Firestore emulator. Use the Cloud Firestore emulator to run and automate unit tests in a local environment before you deploy any changes.

To quickly test your updated Cloud Firestore Security Rules in the Firebase console, use the Simulator tool.

  1. To open the Simulator, click Simulator from the Rules tab.
  2. In the Simulator settings, select options for your test, including:
    • Testing reads or writes
    • A specific Location in your database, as a path
    • Authentication type — unauthenticated, authenticated anonymous user, or a specific user ID
    • Document-specific data that your rules specifically reference (for example, if your rules require the presence of a specific field before allowing a write)
  3. Click Run and look for the results in the banner above the rules window.

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