This repository contains a way to run code inside the Wii U's web browser. It provides a means to execute arbitrary code in the Cafe OS userspace on the Espresso processor. It does not allow running code in Espresso kernel-mode or provide any access to the Starbuck. We hope to implement this in the future, but the exploit is currently limited to userspace only.
Right now, almost all firmware versions are compatible:
- Firmware versions 2.0.0 (first instalment of the Internet Browser) to 5.1.0 are supported by exploiting an use-after-free bug (CVE-2013-2842).
- Firmware version 5.3.2 is supported by exploiting a memory corruption bug (CVE-2014-1300).
- Firmware versions 5.1.1 to 5.3.1 are also supported, but currently unimplemented.
- Firmware version 5.4.0 is not supported yet.
Inside this repository, you will find a set of tools that allow you to compile your own C code and embed it inside a webpage to be executed on the Wii U. There are also a few code examples doing certain tasks on the Wii U. Most notably, there is an RPC client which allows your Wii U to execute commands sent over the network from a Python script. Nothing in this repository is useful to the general public. You will only find it useful if you are a C programmer and want to explore the system by yourself.
How do I use this?
C build system
- Unix-like shell environment (use Cygwin to get this on Windows)
- devkitPPC (needed to compile and link the C code), with
- Python 3.x (must add
PATH) or 2.x
osscreenexamples folder contains projects using
OSScreen and the
examples folder does not use
OSScreen and uses the
loader.c in the
projects local directory.
python build.py <project path>
python build.py osscreenexamples/template
Accessing the SDK libraries
When you're writing C code on a PC, you have the standard library, a set of useful functions that you can call without caring how they work. For writing code on the Wii U, there's something similar: the SDK libraries. The SDK libraries provide access to graphics, audio, input, filesystem, and network functions. They are accessible from any application, including the web browser, which means that code running inside it using an exploit also gets access. All SDK libraries have full symbols available for every function. This means that you can get the address of any function by its library and symbol name.
Every SDK library is an RPL file, a modification of the ELF format. For example,
gx2.rpl is the name of the graphics library,
vpad.rpl is the name of the Gamepad input library, and
nsysnet.rpl is the name of the BSD sockets library. There is also a special RPL called
coreinit.rpl, which provides direct access to many core Cafe OS services, including memory management and threading.
So how do you get the addresses of SDK functions? You could just hardcode them, obviously, but that's both lame and not portable to later exploit versions. There's a much better method available, which allows you to get symbol addresses dynamically, in the form of the
OSDynLoad functions. You can access these functions by including
coreinit.h in your C file.
There are two functions involved in getting a symbol, splitting the process into two parts. The first function is
OSDynLoad_Acquire(), which loads the RPL you specify.
OSDynLoad_Acquire() takes two arguments: the RPL name and a pointer to an integer handle.
OSDynLoad_Acquire() can also be used to get a handle to a library that's already loaded. The second function is
OSDynLoad_FindExport(), which finds a symbol given a library's location. It takes four arguments: the integer handle returned by
OSDynLoad_Acquire(), whether the symbol is data or not (usually not), the symbol name, and a pointer to where the symbol address should be stored. Here are the function prototypes:
void OSDynLoad_Acquire(char \*rplname, unsigned int \*handle);
void OSDynLoad_FindExport(unsigned int handle, int isdata, char \*symname, void \*address);
Just as an example, let's say I wanted the
VPADRead() symbol from
vpad.rpl. If I have an integer called
handle, I first call
OSDynLoad_Acquire("vpad.rpl", &handle); to get the RPL's location. Next, if I have a function pointer for
VPADRead, I call
OSDynLoad_FindExport(handle, 0, "VPADRead", &VPADRead); to retrive
VPADRead()'s address. Simple. For more examples, look at
In addition to letting you write your own C code to run on the Wii U, this repository also includes an RPC system to interactively experiment with the Wii U. It allows you to send commands over the network for your Wii U to execute. The two components of the RPC system are the server, a C program running on the Wii U listening for commands, and the client, a Python script that sends the commands.
To use the RPC system, first ensure that your PC and Wii U are connected to the same network. Once they are, find out your PC's IP address using the
ipconfig command (Windows) or
ifconfig command (Linux and OS X). Modify
socket.h to be your PC's IP address (rather than
192.168.1.4, which it currently is). Build
rpc.c and it will go in your
rpc.py in an interactive Python session (IDLE or IPython is a good choice). Once you've started
rpc.py, navigate to the browser exploit you just made on your Wii U. It should appear to finish loading the page, and the UI will continue to be responsive, but web browsing will be disabled. At that point, the Python shell should say something along the lines of "Connected by" followed by your Wii U's IP. Now you can control your Wii U with these commands:
rpc.read32(address, num_words)- Read
num_wordswords starting at
address, returning a list of words
rpc.write32(address, words)- Write each word in the list
wordsto memory starting at
rpc.dump_mem(address, length, filename)- Dump
lengthbytes from memory starting at
symbol(rplname, symname)- Get the symbol
rplnameand turn it into a callable Python function
rpc.exit()- Exit the browser and go back to the menu