Easy Replace Image <= 3.5.2 - Missing Authorization to Authenticated (Contributor+) Arbitrary Attachment Replacement

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.