OpenStack Nova-LXD before 13.1.1 uses the wrong name for the veth pairs when applying Neutron security group rules for instances, which allows remote attackers to bypass intended security restrictions.
https://github.com/openstack/nova-lxd/commit/1b76cefb92081efa1e88cd8f330253f857028bd2
https://bugs.launchpad.net/nova-lxd/+bug/1656847
http://www.ubuntu.com/usn/USN-3195-1