source: http://www.securityfocus.com/bid/22222/info

Apple Software Update is prone to a format-string vulnerability.

This issue presents itself because the application fails to properly sanitize user-supplied input before passing it as the format specifier to a formatted-printing function.

A successful attack may crash the application or possibly lead to arbitrary code execution. This may facilitate unauthorized access or privilege escalation in the context of the user running the application. 

$ touch %x.%x.%x.%x.%x.%x.%x.swutmp
$ open %x.%x.%x.%x.%x.%x.%x.swutmp