EC-CUBE plugin 'Product Image Bulk Upload Plugin' 1.0.0 and 4.1.0 contains an insufficient verification vulnerability when uploading files. Exploiting this vulnerability allows a remote unauthenticated attacker to upload arbitrary files other than image files. If a user with an administrative privilege of EC-CUBE where the vulnerable plugin is installed is led to upload a specially crafted file, an arbitrary script may be executed on the system.