source: http://www.securityfocus.com/bid/40173/info


PHP is prone to multiple format-string vulnerabilities because it fails to properly sanitize user-supplied input before passing it as the format specifier to a formatted-printing function.

Attackers can exploit these issues to run arbitrary code within the context of the PHP process. This may allow them to bypass intended security restrictions or gain elevated privileges.

PHP 5.3 through 5.3.2 are vulnerable. 

$ php -r "fopen('phar:///usr/bin/phar.phar/*%08x-%08x-%08x-%08x-%08x-%08x-%08x-%08x-%08x','r');"