Take a Jailbreak -Stunning Guards for iOS Jailbreak- presented at codeblue 2017

by Kaoru Otsuka,

Summary : In this talk, I investigate several exploiting ideas for iOS kernel jailbreak using recently exposed vulnerabilities. Recently, Ian Beer found the following promising vulnerabilities:
CVE-2016-7637: Broken kernel mach port name ‘uref’ handling on iOS/MacOS can lead to privileged port name replacement in other processes,
CVE-2016-7644: XNU kernel UaF due to lack of locking in set_dp_control_port,
CVE-2016-7661: MacOS/iOS arbitrary port replacement in powerd.
However, naive combination of the above vulnerabilities cannot easily break recent mitigations implemented in iOS versions. Recent iOS provides the kernel level mitigations against exploitation such as kernel patch protection, sandboxing, AMFI(Apple Mobile File Integrity), MAC(Mandatory Access Control) policy, KASLR(Kernel ASLR) etc. These mitigations will be briefly explained.