The Juniper Networks NetScreen Firewall devices with ScreenOS before 6.3r17, when configured to use the internal DNS lookup client, allows remote attackers to cause a denial of service (crash and reboot) via a sequence of malformed packets to the device IP.
http://secunia.com/advisories/59026
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10632