jelbrekTime

A developer jailbreak for Apple watch S3 watchOS 4.1
Running this on an apple watch series 3 on watchOS 4.1 will:

Features

• Exploits kernel using v0rtex
• Gets tfp0 and stores it to hsp4
• Applies h3lix kernelpatches
• Remounts / as rw
• Extracts bootstrap.tar

Kernelpatches

• Sets i_can_has_debugger = 1
• Patches remount to allow remounting / as rw
• Patches mount to allow mounting without nosuid
• Sets proc_enforce = 0
• Disables amfi code signature checks
• Allows rwx mappings (for cool watch tweaks?)
• Disables a bunch of sanbox stuff (likely incomplete)

How to run

• Clone git repo
• Open in Xcode
• Select certificate for main app/watch app/watch extension
• Build and run iOS app on Phone
  • On the phone go to Settings->General->Profiles and trust your certificate
  • Run iOS app on the phone through Xcode again
• Open jailbreak.m and set a breakpoint at the bottom where it says 'SET A BREAKPOINT HERE'
• Build and run Watchkit App on the watch
  • Wait for the app to install (this takes ages!!!)
  • Wait for Xcode to tell you launching failed
  • Launch the app manually on the watch
  • Accept the trust certificate on the watch
  • DO NOT CLICK jelbrekTime YET!
• Run the Watchkit App through Xcode again!
  • Again wait for the app to install (this takes ages!!!)
• Click on jelbrekTime button in Watchkit App
• Wait for the breakpoint to hit in Xcode
• Now you can execute shell commands through the debugger by typing:
  • 'p mysystem("ls /")'
  • 'p mysystem("id")'
  • 'p mysystem("ps aux")'

Update: SSH is now working :D
To connect to the watch you want to use companion_proxy by qwertyoruiop

Support more devices

If you want to run this on anything other than Apple Watch S3 on 4.1 You need to modify this project

watchOS 4.0-4.1

Simply add more offsets to offsetfinder.c and you should be good to go.
For finding offsets you can download watch OTA updates from ipsw.me and run offsetfinder.

watchOS 3.x

While watchOS 3.x (iOS 10.x) is vulnerable to v0rtex, structs like kport_t is different to watchOS 4. To port jelbrekTime to 3.x you need to modify kport_t (and possibly other things) to get v0rtex running. You also very likely need to make some changes to the kernelpatches.
Some resources to get started are doubleH3lix and liboffsetfinder64 (obviously those projects are 64bit, but you need to do similar stuff to a 32bit kernel).

Credits

• Siguza
• qwertyoruiop
• jk9357

Special thanks to @coolstarorg for compiling the bootstrap.tar for armv7k!