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.)

Affected: Ubuntu:16.04:LTS: neutron

Erik Olof Gunnar Andersson discovered that OpenStack Neutron incorrectly handled certain security group rules in the iptables firewall module. An authenticated attacker could possibly use this issue to block further application of security group rules for other instances.