Bundled SDK Ships a Vulnerable Exported Component

← Supply Chain (OWASP Mobile M2)

sdk_exported_component_redirection   HARD

Description

A bundled third-party SDK ships its own vulnerable exported component that intent-redirects, so another app abuses the SDK (not the host app’s code) to reach private data / credentials (EngageLab SDK, 50M+ installs).

How it works

The vulnerability is not in the host app’s own code; it ships inside a bundled third-party SDK (the EngageLab SDK class, 50M+ installs). The SDK’s exported component takes a forwarded/nested intent and redirects to the embedded target without validating the destination. Because the SDK runs with the host app’s identity and permissions, another app can route the redirect at a private component (an internal AccountCredentialsProvider) and exfiltrate credentials the host can reach. The lesson: auditing your own code is not enough, a dependency’s exported component can expose you, and only updating or removing the SDK (or the platform hardening it) fixes it. This is an offline, deterministic simulation. The secure handler allowlists only the SDK’s own public endpoints and refuses external/private redirect targets.

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: jadx, adb, drozer, apktool · iOS: ipsw, class-dump.
2. Locate the target. From the home index, open Bundled SDK Ships a Vulnerable Exported Component (sdk_exported_component_redirection). 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-0364, MASTG-TEST-0372 for the canonical procedure and remediation.

Tools (optional)

Android

• jadx
• adb
• drozer
• apktool

iOS

• ipsw
• class-dump