The client in FreeIPA 2.x and 3.x before 3.1.2 does not properly obtain the Certification Authority (CA) certificate from the server, which allows man-in-the-middle attackers to spoof a join procedure via a crafted certificate.
Sumit Bose discovered that FreeIPA's directory server (dirsrv) would segfault if an unauthenicated user attempted to connect to it with a missing username/dn. According to RFC 3062, connecting without specifying the username/dn is valid.
Acknowledgements:
This issue was discovered by Sumit Bose of Red Hat.