source: https://www.securityfocus.com/bid/67911/info

Seo Panel is prone to a directory-traversal vulnerability because it fails to sufficiently sanitize user-supplied input.

Remote attackers can use a specially crafted request with directory-traversal sequences ('../') to retrieve arbitrary files in the context of the application. Information obtained could aid in further attacks.

Seo Panel 3.4.0 is vulnerable; other versions may also be affected. 

http://www.example.com/seopanel/download.php?file=/etc/purple/prefs.xml