The Qi Blocks plugin for WordPress is vulnerable to unauthorized access due to a missing capability check on the resize_image_callback() function in all versions up to, and including, 1.4.3. This is due to the plugin not properly verifying that a user has permission to resize a specific attachment. This makes it possible for authenticated attackers, with Contributor-level access and above, to resize arbitrary media library images belonging to other users, which can result in unintended file writes, disk consumption, and server resource abuse through processing of large images.