Custom Field Template <= 2.7.8 - Authenticated (Contributor+) Insecure Direct Object Reference to Arbitrary Media File Deletion via 'file_field' Parameter

The Custom Field Template plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.7.8 via the edit_meta_value due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to delete arbitrary media attachments site-wide by supplying any numeric attachment ID in the file-field parameter alongside the corresponding delete flag, causing content loss and broken pages. Exploitation requires that the attacker's post is governed by a Custom Field Template containing at least one file-type field with the mediaRemove option not enabled, which is the default configuration for file fields.