How to fix open Firebase security rules

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    // Users can read/write their own document
    match /users/{userId} {
      allow read, write: if request.auth != null && request.auth.uid == userId;
    }

    // Posts: authenticated users can read; only author can modify
    match /posts/{postId} {
      allow read: if request.auth != null;
      allow create: if request.auth != null && request.resource.data.authorId == request.auth.uid;
      allow update, delete: if request.auth != null && resource.data.authorId == request.auth.uid;
    }

    // Default deny
    match /{document=**} {
      allow read, write: if false;
    }
  }
}

rules_version = '2';
service firebase.storage {
  match /b/{bucket}/o {
    match /users/{userId}/{allPaths=**} {
      allow read, write: if request.auth != null && request.auth.uid == userId;
    }
    match /{allPaths=**} {
      allow read, write: if false;
    }
  }
}