source: https://www.securityfocus.com/bid/37393/info

QuiXplorer is prone to a local file-include vulnerability because it fails to sufficiently sanitize user-supplied data.

Exploiting this issue may allow an attacker to compromise the application and the underlying system; other attacks are also possible.

QuiXplorer 2.4.1beta is vulnerable; other versions may also be affected. 

http://www.example.com/path/?lang=../path/to/malicious_uploaded_code