Cisco Nx-os 4.1.(5) Denial Of Service Vulnerability
19 Jan. 2017
Cisco NX-OS 4.1 through 7.2 on Nexus 2000, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote attackers to cause a denial of service (device crash) via crafted IPv4 DHCP packets to the (1) DHCPv4 relay agent or (2) smart relay agent, aka Bug IDs CSCuq24603, CSCur93159, CSCus21693, and CSCut76171.
A vulnerability in the implementation of the DHCPv4 relay agent and smart 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 crafted DHCPv4 offer packets. An attacker could exploit this vulnerability by sending crafted DHCPv4 offer 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 crafted DHCP packets processed by a DHCP relay agent or smart relay agent listening on the device using the IPv4 broadcast address or the IPv4 unicast address of any interface configured on a device.