SQL injection vulnerability in FlexCustomer 0.0.4 and earlier allows remote attackers to bypass authentication and execute arbitrary SQL commands via the admin and ordinary user interface, probably involving the (1) checkuser and (2) checkpass parameters to (a) admin/index.php, and (3) username and (4) password parameters to (b) index.php.  NOTE: it was later reported that 0.0.6 is also affected.