The Enable Media Replace WordPress plugin before 4.1.3 unserializes user input via the Remove Background feature, which could allow Author+ users to perform PHP Object Injection when a suitable gadget is present on the blog
The Enable Media Replace WordPress plugin before 4.0.2 does not prevent authors from uploading arbitrary files to the site, which may allow them to upload PHP shells on affected sites.
The Enable Media Replace WordPress plugin before 4.0.0 does not ensure that renamed files are moved to the Upload folder, which could allow high privilege users such as admin to move them outside to the web root directory via a path traversal attack for example