PowerDNS before 2.9.18, when running with an LDAP backend, does not properly escape LDAP queries, which allows remote attackers to cause a denial of service (failure to answer ldap questions) and possibly conduct an LDAP injection attack.
http://www.securityfocus.com/bid/14290
http://www.novell.com/linux/security/advisories/2005_19_sr.html
http://securitytracker.com/id?1014504