The Internationalized Domain Name (IDN) feature in Apple Safari before 5.1.4 on Windows does not properly restrict the characters in URLs, which allows remote attackers to spoof a domain name via unspecified homoglyphs.
http://www.securitytracker.com/id?1026785
http://secunia.com/advisories/48377
http://lists.apple.com/archives/security-announce/2012/Mar/msg00003.html