The handle_connection_error function in ldap_helper.c in bind-dyndb-ldap before 1.1.0rc1 does not properly handle LDAP query errors, which allows remote attackers to cause a denial of service (infinite loop and named server hang) via a non-alphabet character in the base DN in an LDAP search DNS query.
https://www.redhat.com/archives/freeipa-users/2012-April/msg00144.html
https://git.fedorahosted.org/cgit/bind-dyndb-ldap.git/tree/NEWS
https://bugzilla.redhat.com/show_bug.cgi?id=815846
http://www.openwall.com/lists/oss-security/2012/04/24/15