Installed-App Enumeration (Privacy Fingerprint)

← Privacy (OWASP Mobile M6)

installed_app_enumeration   EASY

Description

The app probes which OTHER apps are installed - iOS canOpenURL over a scheme list, Android queryIntentActivities / getInstalledPackages - with no functional need, building a device fingerprint and crossing a privacy boundary (iOS CVE-2026-20641 installed-apps disclosure class).

How it works

The app probes which other apps are installed (iOS canOpenURL over a scheme list, Android queryIntentActivities / getInstalledPackages) with no functional need. The detected set is a stable device fingerprint that reveals sensitive traits (dating, health, finance, secure-messaging apps) across a privacy boundary (iOS CVE-2026-20641 installed-apps disclosure class). This offline demo holds an installed-app set and a probe list in memory. The secure path only checks the single scheme the app legitimately needs, with a declared purpose, so no broad fingerprint is built.

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 Privacy (OWASP Mobile M6) 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, frida-trace · Android: jadx, apktool · iOS: ipsw, class-dump.
2. Locate the target. From the home index, open Installed-App Enumeration (Privacy Fingerprint) (installed_app_enumeration). 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. Trigger the data-access/telemetry path and confirm sensitive data is collected, transmitted, or associated without the required consent / transparency prompt.
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-0255, MASTG-TEST-0024 for the canonical procedure and remediation.

Tools (optional)

• frida
• frida-trace

Android

• jadx
• apktool

iOS

• ipsw
• class-dump

Real-world references

Concrete public disclosures that match this vulnerability class:

• About the security content of iOS 18.7.5 (CVE-2026-20641 installed-apps disclosure)