Cisco Security Advisory: Cisco NX-OS Software Crafted DHCPv4 Packet Denial of Service Vulnerability

[Cisco Systems Product Security Incident Response Team <psirt@xxxxxxxxx>]

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Cisco Security Advisory: Cisco NX-OS Software Crafted DHCPv4 Packet Denial of 
Service Vulnerability

Advisory ID:  cisco-sa-20161005-dhcp1

Revision: 1.0

For Public Release: 2016 October 5 16:00  GMT

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Summary
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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.

Cisco has released software updates that address this vulnerability. There are 
no workarounds that address this vulnerability. 

This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161005-dhcp1

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