Juan Pablo Lopez Yacubian has discovered two vulnerabilities in Safari, which can be exploited by malicious people to conduct spoofing attacks or potentially compromise a user's system.

1) An error when downloading e.g. a .ZIP file with an overly long filename can be exploited to cause a memory corruption.

Successful exploitation may allow execution of arbitrary code.

2) An error in the handling of windows can be exploited to display arbitrary content while showing the URL of a trusted web site in the address bar.

The vulnerabilities are confirmed in version 3.1 for Windows. Other versions may also be affected.

http://secunia.com/advisories/29483/