source: https://www.securityfocus.com/bid/25698/info

Coppermine Photo Gallery is prone to a cross-site scripting issue and a local file-include issue.

Attackers can exploit these issues to steal cookie-based authentication credentials, execute arbitrary code, and retrieve arbitrary content within the context of the webserver process.

Coppermine Photo Gallery 1.4.12 is vulnerable; other versions may also be affected. 

http://www.example.com/cpg/mode.php?admin_mode=1&referer=javascript:alert(document.cookie)