The token processing system (pki-tps) in Red Hat Certificate System (RHCS) before 8.1.3 allows remote attackers to cause a denial of service (Apache httpd web server child process restart) via certain unspecified empty search fields in a user certificate search query.
https://bugzilla.redhat.com/show_bug.cgi?id=869579
http://www.securitytracker.com/id?1027846
http://www.securityfocus.com/bid/56843