An issue was discovered in the iptables firewall module in OpenStack Neutron before 10.0.8, 11.x before 11.0.7, 12.x before 12.0.6, and 13.x before 13.0.3. By setting a destination port in a security group rule along with a protocol that doesn't support that option (for example, VRRP), an authenticated user may block further application of security group rules for instances from any project/tenant on the compute hosts to which it's applied. (Only deployments using the iptables security group driver are affected.)
A flaw was found in openstack-neutron. When merging port ranges, the code never assumed the conjunction ID might not be present in the set due to already being removed. This can lead to server crash and denial of service.
Upstream patch:
https://review.openstack.org/#/c/640252/ https://review.openstack.org/#/c/648102/2 https://review.openstack.org/#/c/648004/2 https://review.openstack.org/#/c/648003/2 https://review.openstack.org/#/c/648002/2
References:
https://bugs.launchpad.net/ubuntu/+source/neutron/+bug/1813007 https://bugs.launchpad.net/ossa/+bug/1813007 https://review.openstack.org/#/q/topic:bug/1813007