The Apple Type Services (ATS) server in Mac OS X 10.4.8 and earlier does not securely create log files, which allows local users to create and modify arbitrary files via unspecified vectors, possibly relating to a symlink attack.
http://www.vupen.com/english/advisories/2006/4750
http://www.us-cert.gov/cas/techalerts/TA06-333A.html
http://www.securityfocus.com/bid/21335
http://www.kb.cert.org/vuls/id/323424
http://securitytracker.com/id?1017301
http://secunia.com/advisories/23155
http://lists.apple.com/archives/security-announce/2006/Nov/msg00001.html