Problem loading the website using Firebase when using Burp Proxy

Question

Let's say I use the website: redacted.com
Website works fine when I am using it normally.
When I start using BURP SUITE PROXY to intercept requests, I start to have this error:

[2021-04-14T02:45:46.724Z]  @firebase/firestore: Firestore (7.24.0): Could not reach Cloud Firestore backend. Backend didn't respond within 10 seconds.
This typically indicates that your device does not have a healthy Internet connection at the moment. The client will operate in offline mode until it is able to successfully connect to the backend.

Error: Uncaught (in promise): FirebaseError: [code=unavailable]: Failed to get document because the client is offline.

Please provide me the solution to this.

Answer 1

Faced the same issue. What worked for me is adding “firestore.googleapis.com” to the “No proxy for” option in Firefox’s proxy configuration.

Firefox Proxy Configuration

Answer 2

Using the idea of this troubleshoot (https://github.com/firebase/firebase-js-sdk/issues/1190#), i made the following Match and Replace in my Burp Suite and it worked!

this.forceLongPolling=void 0!==t.experimentalForceLongPolling&&t.experimentalForceLongPolling

to

this.forceLongPolling=true

And someone said before

This can change depending on the version of firebase-js-sdk so it's best to look around for experimentalForceLongPolling within your JS files and make sure it gets enabled.

Answer 3

Workaround for this issue (source).

For Burp, the following match and replace worked for me:

this.experimentalForceLongPolling=!!t.experimentalForceLongPolling

to

this.experimentalForceLongPolling=true

This can change depending on the version of firebase-js-sdk so it's best to look around for experimentalForceLongPolling within your JS files and make sure it gets enabled.

Answer 4

The answers do not work anymore due to the Firebase updates - i will give you a short instruction on how to find your custom match-replace rule:

• make sure to activate "Intercept Server Responses" in the proxy options tab.

• go "intercept" tab

• set your burp proxy to "intercept is on"

• type "this.forceLongPolling" in the search bar on the bottom

• forward the requests until you find a match

• there should be a pretty big response file containing something like this:

constructor(t,o,u,p,D,Q,Te,it){
    this.databaseId=t,this.appId=o,this.persistenceKey=u,this.host=p,this.ssl=D,this.forceLongPolling=Q,this.autoDetectLongPolling=Te,this.useFetchStreams=it
}

• in my case it contains the string "this.forceLongPolling=Q"

• now create a match replace rule for this very special string to replace "this.forceLongPolling=Q" with "this.forceLongPolling=true" and make sure to choose "response body" as type:

Screenshot Rule