I thought of making a small challenge in exploiting format strings in Windows. This is how it looks, it asks for a filename to open. At first this might be a bit confusing. There’s no vulnerable functions in reading a file. You can see that our first argument to the program is echoed back in the program.
Let’s investigate this inside a debugger. As you can see if argc == 2 the application continues the flow and argv is passed into that function highlighted.