Apple has shipped new versions of its Safari browser with patches for at least 48 security vulnerabilities. The Safari 4.1 and 5.0 updates, considered highly critical, are available for both Windows and Mac OS X. Exploitation of some of these vulnerabilities could lead to drive-by download (remote code execution) attacks. The majority of the documented vulnerabilities affected WebKit, the open-source Web browser engine that powers Safari. Safari supports the inclusion of user information in URLs, which allows the URL to specify a username and password.
Source: https://threatpost.com/apple-plugs-48-security-holes-safari-browser-060810/74072/