The Easy Replace Image plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 3.5.2. This is due to missing capability checks on the `image_replacement_from_url` function that is hooked to the `eri_from_url` AJAX action. This makes it possible for authenticated attackers, with Contributor-level access and above, to replace arbitrary image attachments on the site with images from external URLs, potentially enabling site defacement, phishing attacks, or content manipulation.
