The DHCP relay agent in Cisco Adaptive Security Appliance (ASA) and PIX 7.2 allows remote attackers to cause a denial of service (dropped packets) via a DHCPREQUEST or DHCPINFORM message that causes multiple DHCPACK messages to be sent from DHCP servers to the agent, which consumes the memory allocated for a local buffer. NOTE: this issue only occurs when multiple DHCP servers are used.
https://exchange.xforce.ibmcloud.com/vulnerabilities/34026
http://www.vupen.com/english/advisories/2007/1635
http://www.securitytracker.com/id?1018000
http://www.securitytracker.com/id?1017999
http://www.securityfocus.com/bid/23763
http://www.kb.cert.org/vuls/id/530057
http://www.cisco.com/en/US/products/products_security_response09186a0080833172.html