Cisco Nx-os 4.1.(3) Denial Of Service Vulnerability
18 Jan. 2017
Cisco NX-OS 4.1 through 7.3 and 11.0 through 11.2 on Nexus 2000, 3000, 3500, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote attackers to cause a denial of service (device crash) via malformed IPv4 DHCP packets to the DHCPv4 relay agent, aka Bug IDs CSCuq39250, CSCus21733, CSCus21739, CSCut76171, and CSCux67182.
A vulnerability in the implementation of the DHCPv4 relay agent in Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
The vulnerability is due to improper validation of malformed DHCPv4 packets. An attacker could exploit this vulnerability by sending malformed DHCPv4 packets to an affected device. An exploit could allow the attacker to cause the DHCP process or device to crash.
This vulnerability can be exploited using IPv4 packets only. The vulnerability can be triggered by malformed DHCP packets processed by a DHCP relay agent listening on the device, using the IPv4 broadcast address or IPv4 unicast address of any interface configured on a device.