The Mach kernel, as used in operating systems including (1) Mac OS X 10.4 through 10.4.7 and (2) OpenStep before 4.2, allows local users to gain privileges via a parent process that forces an exception in a setuid child and uses Mach exception ports to modify the child's thread context and task address space in a way that causes the child to call a parent-controlled function.

The Mach kernel, as used in operating systems including (1) Mac OS X 10.4 through 10.4.7 and (2) OpenStep before 4.2, allows local users to gain privileges via a parent process that forces an exception in a setuid child and uses Mach exception ports to modify the child's thread context and task address space in a way that causes the child to call a parent-controlled function.