Unsigned / Unverified Build Artifact

← Supply Chain (OWASP Mobile M2)

unsigned_unverified_build_artifact   MEDIUM

CategorySupply Chain (OWASP Mobile M2)
OWASP Mobile (2024)M2
MASVSMASVS-RESILIENCE-3MASVS-CODE-1
MASWEMASWE-0057
CWECWE-347CWE-494
PlatformAndroidiOS

Description

Update artifact fetched and applied with no signature/checksum check.

How it works

The in-app updater fetches an artifact over the network and applies it with no signature and no checksum comparison against a trusted value. An on-path attacker swaps in a trojaned artifact and it installs unchanged. Apply a “tampered” artifact below.

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: Android: apksigner, apktool · iOS: codesign.
  2. Locate the target. From the home index, open Unsigned / Unverified Build Artifact (unsigned_unverified_build_artifact). 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.

Tools (optional)

Android

iOS