The Avaya 4602 SW IP Phone (Model 4602D02A) with 2.2.2 and earlier SIP firmware allows remote attackers to cause a denial of service (device reboot) via a flood of packets to the BOOTP port (68/udp).
https://exchange.xforce.ibmcloud.com/vulnerabilities/34970
http://www.sipera.com/index.php?action=resources%2Cthreat_advisory&tid=301&
http://support.avaya.com/elmodocs2/security/ASA-2007-263.htm