By forging non-IP traffic such as DHCP discovery or ARP messages, an instance may spoof IP or MAC source addresses on attached networks resulting in denial of services and/or traffic interception. Moreover when L2population isn't used, other tenants attached to a shared network are also vulnerable. Neutron setups using the IPTables firewall driver are affected.
Thank you Dustin for this review! How about:
By forging non-IP traffic such as DHCP discovery or ARP messages, an instance may spoof IP or MAC source addresses on attached networks resulting in denial of services and/or traffic interception. Moreover when L2population isn't used, other tenants attached to a shared network are also vulnerable. Neutron setups using the IPTables firewall driver are affected.