Arbitrary file upload in DoubleScale All-in-One CRM plugin

The DoubleScale | All-in-One CRM – Sales, Multi-Channel Marketing, Newsletter, Booking, Helpdesk, Automation, MCP & More plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.5.1 via the store_upload function. This is due to a fail-open extension allow-list in extension_is_allowed() that returns true when wp_check_filetype() yields an empty type for unrecognized extensions such as .php, combined with magic-byte-only MIME detection and no capability check beyond is_user_logged_in(). This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. Exploitation requires the Helpdesk module to be enabled, as the vulnerable REST endpoint is only registered when that module is active.