GOOGLE FIRESTORE: Are these security rules safe?

Question

So I am going through the security rules documentation of firestore right now in an effort to make sure the data users put in my app will be okay. As of right now, all I need users to be able to do is to read data (really only the 'get', but 'read' is fine too), and create data. So, my security rules for the firestore data right now are:

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /jumpSpotAnnotations/{id} {
      // 'get' instead of 'read' would work too
      allow read, create;
    }
  }
}

I have the exact same 'allow read, create;' for my storage data too. Will this be okay upon release or is this dangerous? In the documentation, they write:

"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."

This text precedes an example where the rules are, 'allow read, write;', as opposed to my 'allow read, create'. Are my rules also subject to the deletion/modification of the data? I put create because I assume that that only lets people create the data, and not delete or modify it.

Final part of this question, but how could a user guess my project ID? Would they not have to sign in on my google account to then be able to manually delete, modify, or steal data? I'm not sure how that works. My app interface allows for the user to only create data, or read data, nothing else. So could some random person still somehow get into this database online and mess with it?

Thanks for any help.

Answer 1

Your rule allows anyone with an internet connection to read and create documents in the jumpSpotAnnotations collection. We don't know if that's "safe" for your app. You have to determine for yourself if that situation is safe. If you're OK with someone anonymously loading up that collection with documents, and you're OK with paying for that behavior, then it's safe.

Your project ID is baked into your app before you publish it. All someone has to do is download and decompile your app to find it. It's not hard. Your project ID is not private information.

Answer 2

No, your rules are not secure, to understand how someone can guess your project id and steal data first you have to understand that Firebase provides a simple REST API to access stored data. All of the data is stored in JSON format, so public databases can be accessed by making a request to the database URL appended by “.json”.

Now the main concern that how someone can guess your project id, see there are many tools available through which you can set up a proxy on your network and analyze each and every request going through. As Google already said that firebase simply uses rest API so the API endpoints can be known easily by intercepting HTTP requests and then if your rules are not secured then your data could be compromised.

Now solution, how to protect your data. See there are many ways even firebase provides tons of ways to secure data just read their docs about database security. But there is something which you could do from your side so that if your data is compromised then also someone can't actually read it. You can prevent the apps from reading the data in plaintext. Use public-key algorithms to encrypt the data. Keep the private key on the systems that have to read the data. Then the app cannot read the data in plain text. This also will not prevent the manipulation or deletion of data.