Toast.makeText(getApplicationContext(), “Invalid Username or password”, Toast.LENGTH_LONG).show() Intent in=new Intent(getApplicationContext(),Welcome.class) To keep the things simple, I am showing the original source as the idea here is to understand how to write Cydia Substrate extension assuming that we have access to the application’s logic.įollowing is the code snippet for Login.java We can decompile the APK and get the Java version of the code to understand the logic.

Obviously, we first need to understand the application’s logic before proceeding with the Substrate extension. Our goal is to bypass this login by writing a Cydia Substrate extension. When the user enters invalid credentials, an error will be thrown as shown in the figure below. Following is our target app’s first activity. Like every other article of mine, we will have a vulnerable app here and then we will exploit it using this Cydia Substrate extension.

Now, Let’s start writing the Substrate extension.

Target application – you can download it here:.

Create a new Android Application (This is the Cydia Substrate extension) using your favorite IDE and add substrate-api.jar library into your libs folder.

Rooted Android Device with Cydia Substrate installed.

Download cydia for android no root