The supersede_lease function in memory.c in ISC DHCP (dhcpd) server 2.0pl5 allows remote attackers to cause a denial of service (application crash) via a DHCPDISCOVER packet with a 32 byte client-identifier, which causes the packet to be interpreted as a corrupt uid and causes the server to exit with "corrupt lease uid."
http://www.vupen.com/english/advisories/2006/3158
http://www.securityfocus.com/bid/19348
http://www.openbsd.org/errata.html#dhcpd
http://www.debian.org/security/2006/dsa-1143
http://securitytracker.com/id?1016755
http://secunia.com/advisories/21655
http://secunia.com/advisories/21363