Cisco NX-OS Internet Group Management Protocol Denial of Service Vulnerability

A vulnerability in the Internet Group Management Protocol version 3 (IGMPv3) input packet processing of Cisco NX-OS could allow an unauthenticated, adjacent attacker to cause the IGMP process to restart due to a malformed IGMP packet, which could cause a denial of service (DoS) condition on the device.

The vulnerability is due to improper input validation when ensuring the memory allocated is large enough for the number of included sources in the IGMPv3 packet. An attacker could exploit this vulnerability by sending a crafted IGMPv3 packet to the targeted device. An exploit could allow the attacker to cause the IGMP process to restart due to a buffer overflow, which may cause a DoS condition.

Cisco has confirmed the vulnerability. Software updates are available.

An unauthenticated, adjacent attacker could use this vulnerability if the targeted device’s IGMPv3 snooping is configured on one or more VLANs and running the affected version of the software.

To exploit this vulnerability, an attacker must be on the same broadcast or collision domain as the affected device. This access requirement could decrease the likelihood of a successful exploit.