| cover | coverY |
|---|---|
../../../../../.gitbook/assets/image.avif |
0 |
Before we go on a jumble to find buttons within a GUI and also start reversing their values- we need to really get behind what specific buttons are and how they may work in a GUI.
The first thing to know is that buttons in applications such as GUIs are usually boiling down to the following inner workings.
{% hint style="info" %} Do not believe that this is all that goes into buttons- there is a LOT more that happens and can be done with them but I want to note the most significant information for this CTF. {% endhint %}
The input to the button is usually going to be someone clicking the button. When the button detects it has been pressed, or a signal has been received by the widget listener, the button that was pressed will tell the button to execute the information.
Usually, buttons will detect their input like this.
if (ButtonPressed(0xdeadbeaf)) {
// Rendering
}
// Continue if it was not pressed
And this condition is executed for each time the frame is rendered.
The result of buttons being pressed can mainly be segmented into two results.
- A global state is written to define what the program should do next
- The button just executes the code and will return like normal
For our scenario, we analyzed that throughout REplay, the GUI seems to be using some sort of configuration or just a large set of namespaces to globally access information's. For example, the password was never a local variable setup, it was in the same area as the username, adminID, and other relevant storage fields with constant buffer limits.
Since we see this, we can imagine that (especially with control flow analysis) the buttons, for tabs, are setting the current status of a global variable to set the "menutab" in the program which is read and checked before rendering the frame.