OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
github.com/openstack/neutron
github.com/openstack/neutron/commit/0a931391d8990f3e654b4bfda24ae4119c609bbf
github.com/openstack/neutron/commit/cc0d28a3e2ccfad6fc2ff24d78f009cbe3992575
launchpad.net/bugs/1938670
nvd.nist.gov/vuln/detail/CVE-2021-38598
opendev.org/openstack/neutron/commit/fafa5dacd5057120562184a734e7345e7c0e9639