ISC dhcrelay (dhcp-relay) 3.0rc9 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (packet storm) via a certain BOOTP packet that is forwarded to a broadcast MAC address, causing an infinite loop that is not restricted by a hop count.
https://exchange.xforce.ibmcloud.com/vulnerabilities/11187
http://www.securityfocus.com/bid/6628
http://www.redhat.com/support/errata/RHSA-2003-034.html
http://www.openpkg.org/security/OpenPKG-SA-2003.012-dhcpd.html
http://www.kb.cert.org/vuls/id/149953
http://www.debian.org/security/2003/dsa-245
http://marc.info/?l=bugtraq&m=104310927813830&w=2
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000616