Thanks to rik for this:

Apple has shipped another mega-update to address security vulnerabilities affecting Mac OS X users, warning that the most serious issues could lead to arbitrary code execution attacks.

The update, available for Tiger and Leopard, addresses a total of 34 documented vulnerabilities, some in third-party components like ClamAV, BIND, OpenSSH and Ruby.

View: Security content of Mac OS X v10.5.5 and Security Update 2008-006

News source: ZDNet