source: https://www.securityfocus.com/bid/54058/info

Wp-ImageZoom for WordPress is prone to a remote file-disclosure vulnerability because it fails to properly sanitize user-supplied input.

An attacker can exploit this vulnerability to view local files in the context of the web server process, which may aid in further attacks.

Wp-ImageZoom 1.0.3 is vulnerable; other versions may also be affected. 

http://www.example.com/wordpress/wp-content/plugins/wp-imagezoom/download.php?file=../../../../../../../etc/passwd