FreeIPA uses a default password policy that locks an account after 5 unsuccessful authentication attempts, which allows remote attackers to cause a denial of service by locking out the account in which system services run on.
https://pagure.io/freeipa?id=6f1d927467e7907fd1991f88388d96c67c9bff61
https://bugzilla.redhat.com/show_bug.cgi?id=1370493
http://www.securityfocus.com/bid/94934