The uListing plugin for WordPress is vulnerable to authorization bypass due to missing capability and nonce checks on the UlistingUserRole::save_role_api method in versions up to, and including, 1.6.6. This makes it possible for unauthenticated attackers to remove or add roles, and add capabilities.
blog.nintechnet.com/wordpress-ulisting-plugin-fixed-multiple-critical-vulnerabilities/
plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=2456786%40ulisting&new=2456786%40ulisting&sfp_email=&sfph_mail=
www.wordfence.com/threat-intel/vulnerabilities/id/44e112a7-8f51-4d2a-a4b3-74a47ef3aec7?source=cve