Insecure Firebase / Cloud Backend Config

← Supply Chain (OWASP Mobile M2)

insecure_firebase_cloud_config   MEDIUM

Description

A world-readable Firebase/cloud backend URL plus hardcoded cloud credentials expose backend data.

How it works

The Firebase database URL and cloud API key/secret are hardcoded in the app (recoverable with standard reverse-engineering tools, jadx/strings on Android, class-dump/nm/strings on iOS) and the backend rules are world-readable (.read=true). An unauthenticated read therefore returns every user’s records, not just the caller’s. The real check is hitting the exposed endpoint, for example curl https://.firebaseio.com/users.json. A secure backend requires auth and scopes reads to the owner.

How to exercise it. DVMA is the harness - open this module from the home index and tap the demo action. The screen ships the malicious input and simulates the attacker (e.g. the companion app, crafted intent, or scanned payload) in-process, and the evidence panel prints the proof. The Tools (optional) and Attack inputs below are only needed to reproduce the exploit end-to-end on a real device.

Exploit steps

1. Set up. Build DVMA with a flavor that enables the Supply Chain (OWASP Mobile M2) category (e.g. --dart-define-from-file=config/flavors/dev.json) and run on an emulator/simulator you control. The demo needs no external tooling; for the optional on-device reproduction the relevant tools are: mitmproxy, strings, MobSF · Android: jadx, apkleaks · iOS: ipsw, class-dump.
2. Locate the target. From the home index, open Insecure Firebase / Cloud Backend Config (insecure_firebase_cloud_config). The How it works section above describes this module’s specific weakness; the screen states the intended-secure behavior and exposes the vulnerable action.
3. Exploit. Inspect the dependency/SDK surface (lockfiles, bundled SDKs, update channel) and confirm the untrusted or unverified component is accepted - e.g. a substituted package, an unsigned artifact, or a silent post-deploy update.
4. Observe the evidence. Trigger the vulnerable action and read the evidence panel - it prints the concrete proof (leaked value, accepted replay, executed payload, or unauthorized result).
5. Contrast with the secure path. Run the module’s secure/hardened action (where provided) and confirm the same attack is rejected - this is what a correct implementation should do.
6. Map it back. Cross-reference the MASTG v2 test(s) MASTG-TEST-0212, MASTG-TEST-0214 for the canonical procedure and remediation.

Tools (optional)

• mitmproxy
• strings
• MobSF

Android

• jadx
• apkleaks

iOS

• ipsw
• class-dump