oscommerce v2.3.4.1 has a functional problem in user registration and password rechecking, where a non-identical password can bypass the checks in /catalog/admin/administrators.php and /catalog/password_reset.php
osCommerce 2.3.4.1 has an incomplete '.htaccess' for blacklist filtering in the "product" page. Remote authenticated administrators can upload new '.htaccess' files (e.g., omitting .php) and subsequently achieve arbitrary PHP code execution via a /catalog/admin/categories.php?cPath=&action=new_product URI.
osCommerce 2.3.4.1 has an incomplete '.htaccess' for blacklist filtering in the "product" page. Because of this filter, script files with certain PHP-related extensions (such as .phtml and .php5) didn't execute in the application. But this filter didn't prevent the '.pht' extension. Thus, remote authenticated administrators can upload '.pht' files for arbitrary PHP code execution via a /catalog/admin/categories.php?cPath=&action=new_product URI.