Disable Attachment Pages

Hide the Attachment/Attachments pages on the frontend from all visitors.

<?php
add_action(
 'template_redirect',
 function () {
  global $post;
  if ( ! is_attachment() || ! isset( $post->post_parent ) || ! is_numeric( $post->post_parent ) ) {
   return;
  }
  // Does the attachment have a parent post?
  // If the post is trashed, fallback to redirect to homepage.
  if ( 0 !== $post->post_parent && 'trash' !== get_post_status( $post->post_parent ) ) {
   // Redirect to the attachment parent.
   wp_safe_redirect( get_permalink( $post->post_parent ), 301 );
  } else {
   // For attachment without a parent redirect to homepage.
   wp_safe_redirect( get_bloginfo( 'wpurl' ), 302 );
  }
  exit;
 },
 1
);