In-App Browser UI / Address-Bar Spoofing

← Improper Platform Usage

inapp_browser_ui_spoofing   MEDIUM

CategoryImproper Platform Usage
OWASP Mobile (2024)M4
MASVSMASVS-PLATFORM-2
MASWEMASWE-0035
CWECWE-1021CWE-451
PlatformAndroidiOS

Description

An in-app WebView browser derives the displayed origin/address-bar from attacker-controllable content instead of the real committed URL, enabling website spoofing / UI misrepresentation (Firefox Focus CVE-2025-10290 / LINE CVE-2024-5739 trust class).

How it works

The in-app WebView browser builds the origin shown in its address bar from attacker-controllable page content (document.title, a pushState path, or a data: or about: trick) instead of the real committed URL. So the chrome shows a trusted https origin while the page actually loaded is the attacker’s site, and the user trusts a lie and enters credentials (the Firefox Focus CVE-2025-10290 / LINE CVE-2024-5739 trust class). On Android this drives a real in-app WebView: the loaded page sets document.title, and the address bar is driven from that page-controlled title rather than the true committed origin. The secure version always derives the address bar from the true committed origin, ignoring page claims.

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 Improper Platform Usage 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, objection · Android: adb · iOS: xcrun simctl openurl.
  2. Locate the target. From the home index, open In-App Browser UI / Address-Bar Spoofing (inapp_browser_ui_spoofing). 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. From a co-resident/attacker context (adb shell am start/drozer, or a crafted deep link / QR), send the untrusted input to the exported component or WebView and confirm the app performs the unsafe action (navigation, JS execution, file/URI access) with no validation.
  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

Real-world references

Concrete public disclosures that match this vulnerability class: