exploit = exploitation of a vulnerability.
vulnerability = a bug in the code that can be exploited (see above) to edit the original code and insert your own code.
these "location" where you can write code and make the hardware run it is used to execute specific action to get access to usually restricted memory area, or even better to existing kernel function.
Kernel = kernel is the hardware core, usually not accessible by the end user or even a game, or a program launched on the console. only the "operating system" of the console is supposed to have kernel access, it's used to manage the access right for each application (responsible of blocking some memory addresses, or preventing a program from accessing specific hardware, etc.)
So, with exploiting a vulnerability, you can run your own code to redirect the execution of a program to a place which it shouldn't access.
There are two possibilities with this :
- the vulnerability is located on a "user mode", and you can only access what the current program has right to access (for example, the browser has access to wii controller, but not to USB) so your code can also access only the controller, not usb.
- the vulnerability is located on a "kernel mode", it means you have access to the low level administration right of the console. Your own code will have access to ALL the existing functions.
Often, the hacking is done in multiple layer : first you need an entry point (a bug in the browser that you have access : URL and display pages) providing you user level access to modules that the browser have access (cookies manipulation, cache, etc.).
once you have access the the application accessible module, you need to find a bug (a vulnerability) in what's accessible to see if you can run another exploit, etc.
the purpose being to reach a place where you get full control of the console (kernel access).
Exploits are often a time race, for example if there's a vulnerability in the cookie module of the browser, you need to make the browser crash, but write your own code in the cookie memory before the console delete it due to the crash. Sometime, it's not possible, or random. That's why current hacks are not "stable", sometime it works because the console didn't clean the memory yet, sometime the memory is already not accessible to write your code to it.
What possible right now : user mode homebrew.
you create your homebrew, and "copy" the code to the browser's vulnerability place.
when the browser run its code to display the URL, it will run your own code instead because it didn't have verification if the code was official or not.
