The recursor in PowerDNS before 3.0.1 allows remote attackers to cause a denial of service (application crash) via malformed EDNS0 packets.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26100
http://www.vupen.com/english/advisories/2006/1527
http://www.securityfocus.com/bid/17711
http://secunia.com/advisories/20117
http://secunia.com/advisories/19831
http://lists.suse.com/archive/suse-security-announce/2006-May/0004.html
http://doc.powerdns.com/changelog.html#CHANGELOG-RECURSOR-3-0-1