libdns in ISC DHCP 4.2.x before 4.2.5-P1 allows remote name servers to cause a denial of service (memory consumption) via vectors involving a regular expression, as demonstrated by a memory-exhaustion attack against a machine running a dhcpd process, a related issue to CVE-2013-2266.
The logging functionality in dhcpd in ISC DHCP before 4.2.3-P2, when using Dynamic DNS (DDNS) and issuing IPv6 addresses, does not properly handle the DHCPv6 lease structure, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via crafted packets related to a lease-status update.
Buffer overflow in ISC DHCP 4.2.x before 4.2.4-P1, when DHCPv6 mode is enabled, allows remote attackers to cause a denial of service (segmentation fault and daemon exit) via a crafted client identifier parameter.