Preboot eXecution Environment (PXE) server allows remote attackers to cause a denial of service (crash) via certain DHCP packets from Voice-Over-IP (VOIP) phones.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2002-0827
http://www.securityfocus.com/bid/5596
http://www.redhat.com/support/errata/RHSA-2002-165.html
http://www.redhat.com/support/errata/RHSA-2002-162.html