CVE 2018-18573

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.

See the CVE page on Mitre.org for more details.