Apple Safari before 4.0 does not properly check for revoked Extended Validation (EV) certificates, which makes it easier for remote attackers to trick a user into accepting an invalid certificate.
http://www.vupen.com/english/advisories/2009/1522
http://www.securitytracker.com/id?1022346
http://www.securityfocus.com/bid/35353
http://support.apple.com/kb/HT3613
http://secunia.com/advisories/35379
http://lists.apple.com/archives/security-announce/2009/jun/msg00002.html