ISC DHCP 4.x before 4.1-ESV-R12-P1, 4.2.x, and 4.3.x before 4.3.3-P1 allows remote attackers to cause a denial of service (application crash) via an invalid length field in a UDP IPv4 packet.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.