source: http://www.securityfocus.com/bid/15611/info

PHP Doc System is prone to a local file-include vulnerability. This is due to the application's failure to properly sanitize user-supplied input.

This may facilitate the unauthorized viewing of files and unauthorized execution of local PHP code.

PHP Doc System 1.5.1 and prior versions are reported vulnerable; other versions may also be affected. 

http://www.example.com/index.php?show=../File