It was discovered that the default IdM password policies that lock out accounts after a certain number of failed login attempts were also applied to host and service accounts. A remote unauthenticated user could use this flaw to cause a denial of service attack against kerberized services.
A flaw was found that allows any unauthenticated party to easily run DoS attack against kerberized services in FreeIPA/IdM realm.
FreeIPA contains MIT KDC as its main component + FreeIPA is using custom database driver for the KDC. As a side-effect of implementation, FreeIPA is enforcing password policies for all principals, including services which do not use "password" but keytab with randomly-generated/strong key.
Default password policy locks an account after 5 unsuccessful authentication attempts for 10 minutes. An attacker can use this to simply lock-out any principal, including system services.
Upstream patch :
https://git.fedorahosted.org/cgit/freeipa.git/commit/?id=6f1d927467e7907fd1991f88388d96c67c9bff61
Additional dependency :
https://git.fedorahosted.org/cgit/freeipa.git/commit/?id=73f33569c8893610e246b2f44a7aeaec872b37e6