The Drag and Drop Multiple File Upload for Contact Form 7 plugin for WordPress is vulnerable to arbitrary file deletion due to insufficient file path validation in the 'dnd_remove_uploaded_files' function in all versions up to, and including, 1.3.8.7. This makes it possible for unauthenticated attackers to add arbitrary file paths (such as ../../../../wp-config.php) to uploaded files on the server, which can easily lead to remote code execution when an Administrator deletes the message. Exploiting this vulnerability requires the Flamingo plugin to be installed and activated.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.