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.
https://exchange.xforce.ibmcloud.com/vulnerabilities/29281
http://www.vupen.com/english/advisories/2006/3852
http://www.us-cert.gov/cas/techalerts/TA06-275A.html
http://www.securityfocus.com/bid/20271
http://www.securityfocus.com/archive/1/447396/100/0/threaded
http://www.kb.cert.org/vuls/id/838404
http://securitytracker.com/id?1016954
http://securityreason.com/securityalert/1663
http://secunia.com/advisories/22187
http://lists.apple.com/archives/security-announce/2006/Sep/msg00002.html