CFNetwork in Apple Mac OS X 10.5 before 10.5.7 does not properly parse noncompliant Set-Cookie headers, which allows remote attackers to obtain sensitive information by sniffing the network for "secure cookies" that are sent over unencrypted HTTP connections.
http://lists.apple.com/archives/security-announce/2009/May/msg00002.html
http://secunia.com/advisories/35074
http://support.apple.com/kb/HT3549
http://www.securityfocus.com/bid/34926
http://www.securitytracker.com/id?1022214
http://www.us-cert.gov/cas/techalerts/TA09-133A.html