OpenMage magento-lts 20.17.0 before 20.18.2 and 21.0.0-beta1 before 21.0.0-beta3 contains an unrestricted file upload vulnerability because the general/file/protected_extensions blocklist omits phar, php8, and phps. Unauthenticated attackers can upload a .phar file through a product File custom option to a predictable media/custom_options path and request it directly to execute code on servers that map .phar to PHP and serve that directory.