Incomplete blacklist vulnerability in the Quarantine feature in CoreTypes in Apple Mac OS X 10.5 before 10.5.6 allows user-assisted remote attackers to execute arbitrary code via an executable file with the content type indicating no application association for the file, which does not trigger a "potentially unsafe" warning message.
https://exchange.xforce.ibmcloud.com/vulnerabilities/47689
http://www.vupen.com/english/advisories/2008/3444
http://www.us-cert.gov/cas/techalerts/TA08-350A.html
http://www.securitytracker.com/id?1021400
http://www.securityfocus.com/bid/32839
http://support.apple.com/kb/HT3338
http://secunia.com/advisories/33179
http://lists.apple.com/archives/security-announce//2008//Dec/msg00000.html