What are Kernel Privileges

The “kernel” is the core of the code in iOS (or any operating system). Because it needs direct access to all apps as well as hardware, code in the kernel runs in an unrestricted privileged mode. It should be the only code in the system that can do this, but a researcher found a way to allow a some other app to “promote” itself to this privileged (kernel) mode. iOS 15.0.2 fixes the vulnerability that allowed this to happen.