Soundhax 3DS

From GameBrew
Soundhax
Soundhax3ds.png
General
Authornedwill
TypeExploits
Version2020
LicenseMixed
Last Updated2020/12/09
Links
Download
Website
Source
Support Author

Soundhax is a primary homebrew entrypoint that works on firmwares up to 11.3. It is a new exploit that gives you access to the homebrew launcher without needing a game to exploit. This vulnerability exploits the default sound application preinstalled on all 3DS devices. Soundhax (when combined with the Homebrew Launcher) is compatible with versions 9.0.0 through 11.3.0 in the EUR, JPN, KOR, and USA regions.

About This Exploit

There is a bug in the 3DS Sound application where it uses a memcpy function instead of a unicode strncpy variant to copy a song name from mp4 atom tags onto the heap, potentially causing a buffer overflow. The exploit takes advantage of this overflow to control the malloc header of the next heap chunk, which allows for arbitrary writes to memory.

By manipulating the free list and causing a stack overflow, the exploit can turn the arbitrary write primitive into ROP and use the gspwn GPU exploit to write shellcode over the text section of the sound process, allowing for code execution.

Regions and Versions

Version N3DS/N2DS O3DS/2DS
US 1.0-11.3
JPN 1.0-11.3
EUR 1.0-11.3
KOR 4.0-11.3
CHN 4.0-11.3 N/A
TWN 4.1-11.3 N/A

All existing versions of Nintendo 3DS Sound prior to Nintendo fixing the vulnerability are now supported.

If your box is checked, then put otherapp.bin on the root of your SD card along with soundhax.m4a and launch the song from the sound player.

It can be used along Pre9otherapp 3DS to launch an arm9 payload from the SD card on pre 9.0 firms (2.1 - 9.2).

Installation

  1. Download the relevant soundhax-region-console-firmware.m4a file for your device.
  2. Save the soundhax song file and copy to the root of your SD.
  3. Download the otherapp payload for your 3DS version, rename it to otherapp.bin, and copy it to the root of the SD card.
  4. Download the Homebrew Menu and place boot.3dsx in the root of the SD card (if it is not there already).
  5. Insert the SD card into the 3DS and start Nintendo 3DS Sound.
  6. Locate your new song and play it to start the Homebrew Menu!

Fixing the annoying bird: Click through all of the bird tips then close the app normally. When you exploit it it doesn't save the fact that you've opened the app before, so closing and reopening normally seems to fix this.

Media

[3DS] How To Install & Use Soundhax - (DarkFlare)

Thanks

  • Subv and Citra authors - for help emulating sound, this was invaluable
  • plutoo - stage 2 shellcode
  • yellows8 - help with gpu address translation for gspwn, initial JPN support, finished KOR support
  • smea - homebrew launcher
  • d3m3vilurr - EUR, JPN, partial KOR support
  • TuxSH - O3DS offset
  • Konng - Testing EUR payloads
  • cakey - advice and support
  • PPP - teaching me everything I know
  • geohot, comex, j00ru, loki, project zero - inspiring me to pursue bug hunting

External Links

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