MobileMe in Apple Mac OS X 10.5 before 10.5.8 does not properly delete credentials upon signout from the preference pane, which makes it easier for attackers to hijack a MobileMe session via unspecified vectors, related to a "logic issue."
https://exchange.xforce.ibmcloud.com/vulnerabilities/52432
http://www.vupen.com/english/advisories/2009/2172
http://www.us-cert.gov/cas/techalerts/TA09-218A.html
http://www.securityfocus.com/bid/35954
http://support.apple.com/kb/HT3757
http://secunia.com/advisories/36096
http://lists.apple.com/archives/security-announce/2009/Aug/msg00001.html