CFNetwork in Apple Mac OS X 10.4 through 10.4.7 and 10.3.9 allows remote SSL sites to appear as trusted sites by using encryption without authentication, which can cause the lock icon in Safari to be displayed even when the site's identity cannot be trusted.
https://exchange.xforce.ibmcloud.com/vulnerabilities/29277
http://www.vupen.com/english/advisories/2006/3852
http://www.securityfocus.com/bid/20271
http://securitytracker.com/id?1016952
http://secunia.com/advisories/22187
http://lists.apple.com/archives/security-announce/2006/Sep/msg00002.html