Cursor + Firebase Security
Cursor accelerates Firebase development, but AI often generates functional code without security rules. Here's how to fix that.
Why Cursor + Firebase?
Cursor's AI can quickly generate Firebase queries, auth flows, and real-time listeners. Security Rules are complex and often overlooked.
Common Vulnerabilities
These are the security issues we find most often in Cursor apps using Firebase.
No Security Rules Generated
Cursor focuses on client code - Security Rules for Firestore/RTDB are rarely included.
Admin SDK Confusion
AI may suggest Admin SDK patterns that expose service credentials client-side.
Missing Auth State Checks
Generated code may access data without verifying authentication status.
Overly Broad Queries
AI may generate queries that fetch more data than needed or authorized.
What We Check for Cursor + Firebase
Security Rules Audit
Verify Firestore and RTDB have proper Security Rules, not test mode.
Admin SDK Detection
Scan for service account credentials in client code.
Auth Flow Analysis
Check that authentication is verified before data access.
Query Scope
Review queries for appropriate data filtering.
Quick Security Wins
Apply these fixes right now to improve your security.
Ask Cursor to generate Security Rules for your data modelRemove any Admin SDK usage from frontend codeAdd auth state checks before all database operationsUse Firebase Emulator to test Security RulesLimit query scope with where clauses and document pathsThe Bottom Line
Cursor + Firebase is powerful, but you must manually create Security Rules. Ask Cursor to help generate rules, then test them thoroughly.
Secure Your Cursor + Firebase App
Find Security Rules misconfigurations, exposed credentials, and other vulnerabilities before attackers do.
Start Security ScanFrequently Asked Questions
Does Cursor generate Firebase Security Rules automatically?
No, Cursor focuses on client-side JavaScript code and doesn't typically generate firestore.rules or database.rules.json files. You must create Security Rules separately - either ask Cursor to help write them or create them manually in the Firebase console.
How can I use Cursor to help with Firebase Security Rules?
Ask Cursor directly: 'Generate Firestore Security Rules for [describe your data model and access patterns]'. Cursor can write good rules, but always test them in the Firebase Emulator before deploying. The AI may miss edge cases.
Why does Cursor sometimes suggest Firebase Admin SDK in frontend code?
Cursor's AI may confuse client and server contexts. Admin SDK provides full database access and should ONLY be used in server-side code (Cloud Functions, backend servers). If Cursor suggests importing firebase-admin in frontend code, it's a security mistake - use the regular Firebase client SDK instead.
How do I test Firebase Security Rules generated by Cursor?
Use Firebase Emulator Suite: firebase emulators:start. Write rule unit tests with @firebase/rules-unit-testing. Test as authenticated and unauthenticated users. Try to access data you shouldn't - if queries succeed that should fail, your rules need work.