Palasthotel

greatestview

This plugin redirects attachment pages to the post, where they are placed (via 301). If there is no parent page, it redirects back to the WordPress home URL (via 302).
Further, when editing a post, the option to link images to their attachment page is hidden via CSS (except it is selected by default).

Disable Attachment Pages

Redirects attachment pages to the post, where they are placed, and hides backend option to link images to attachment page (if not default).

Ben Huson

The Attachment Taxonomy Support provides better support for media and attachments in WordPress versions before WordPress 3.5+.
In versions of WordPress subsequent to 3.5 it just registers ‘attachment_category’ and ‘attachment_tag’ taxonomies.

Attachment Taxonomy Support

Improved taxonomy support for media and attachments in versions of WordPress prior to 3.5.

Disable Attachment Pages vs Attachment Taxonomy Support