Custom Tabs

Exploiting WebViews # WebViews and Custom Tabs let developers overlay browser functionality inside an app instead of navigating users out to an external browser. That convenience increases the attack surface in Android apps. If the WebView loads attacker-controlled URLs, executes untrusted JavaScript, or exposes native Java methods to the page, it can end up leaking private files or launching unexposed activities on the device. Why does this matter? A WebView is not just a UI widget. It is a mini-browser that runs inside your app’s sandbox, with access to your app’s files, cookies, and any Java objects you hand it. The moment an outside input reaches it, you are effectively giving the web a foothold inside the app process.