App Attestation Not Implemented (server never verifies client)

← Insufficient Resilience

app_attestation_absent   MEDIUM

Description

The backend accepts requests without an app-attestation token proving they come from a genuine, unmodified build, so a repackaged or scripted client is indistinguishable from the real app (MASWE-0056).

How it works

The backend accepts requests without an app-attestation token proving they come from a genuine, unmodified build (Play Integrity app recognition on Android, App Attest on iOS). The app reads its real signing certificate, the identity an attestation token would bind against, but attaches nothing to the request, so a repackaged or scripted client is indistinguishable from the real app; the missing control is the weakness.

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 Insufficient Resilience 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: frida, mitmproxy · Android: Play Integrity API · iOS: App Attest.
2. Locate the target. From the home index, open App Attestation Not Implemented (server never verifies client) (app_attestation_absent). 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. Attach an instrumentation tool (frida/objection) and hook or patch the single client-side check, confirming the protection flips to ‘pass’ and the guarded functionality unlocks.
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.

Tools (optional)

• frida
• mitmproxy

Android

• Play Integrity API

iOS

• App Attest

Attack inputs

Payloads/artifacts you author for the on-device attack. The demo already ships and simulates these in-process (e.g. the malicious companion app / crafted intent is emulated inside the screen), so you only need to craft them to reproduce the exploit on a real device:

• repackaged client