When using the Linux bridge ml2 driver, non-privileged tenants are able to create and attach ports without specifying an IP address, bypassing IP address validation. A potential denial of service could occur if an IP address, conflicting with existing guests or routers, is then assigned from outside of the allowed allocation pool. Versions of openstack-neutron before 13.0.0.0b2, 12.0.3 and 11.0.5 are vulnerable.
https://git.openstack.org/cgit/openstack/neutron/commit/?id=54aa6e81cb17b33ce4d5d469cc11dec2869c762d
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-14635
https://bugs.launchpad.net/neutron/+bug/1757482
https://access.redhat.com/errata/RHSA-2018:3792
https://access.redhat.com/errata/RHSA-2018:2721