The Ninja Forms plugin before 2.9.42.1 for WordPress allows remote attackers to conduct PHP object injection attacks via crafted serialized values in a POST request.
jvn.jp/en/jp/JVN44657371/index.html
jvndb.jvn.jp/jvndb/JVNDB-2016-000064
packetstormsecurity.com/files/137211/WordPress-Ninja-Forms-Unauthenticated-File-Upload.html
www.pritect.net/blog/ninja-forms-2-9-42-critical-security-vulnerabilities
www.rapid7.com/db/modules/exploit/unix/webapp/wp_ninja_forms_unauthenticated_file_upload
ninjaforms.com/important-security-update-always-hurt-ones-love/
wordpress.org/plugins/ninja-forms/changelog/
wpvulndb.com/vulnerabilities/8485