The MB Custom Post Types & Custom Taxonomies WordPress plugin before 2.12.3 does not perform any...

The MB Custom Post Types & Custom Taxonomies WordPress plugin before 2.12.3 does not perform any capability or authentication check before allowing an unauthenticated request to re-run a legacy data migration, letting anyone revert a custom post type or taxonomy definition on sites upgraded from a pre-2.0 release back to its pre-upgrade state. This discards configuration changes an administrator made after upgrading and, where those changes had restricted a definition's visibility, silently re-exposes the definition and its content to anonymous visitors.