CVE-2021-40085

Se ha detectado un problema en OpenStack Neutron versiones anteriores a 16.4.1, 17.x versiones anteriores a 17.2.1 y 18.x versiones anteriores a 18.1.1. Unos atacantes autenticados pueden reconfigurar dnsmasq por medio de un valor extra_dhcp_opts diseñado

An input-validation flaw was found in openstack-neutron, where an authenticated attacker could change the dnsmasq configuration. By crafting extra_dhcp_opts values, the attacker could crash the dnsmasq, change parameters for tenants sharing the same interface, or otherwise alter that daemon’s behavior. This flaw might also be used to trigger a configuration parsing buffer overflow in versions of dnsmasq prior to 2.81. The highest threat from this vulnerability is to system availability, but also threatens data confidentiality and integrity.

David Sinquin discovered that OpenStack Neutron incorrectly handled the default Open vSwitch firewall rules. An attacker could possibly use this issue to impersonate the IPv6 addresses of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. Jake Yip and Justin Mammarella discovered that OpenStack Neutron incorrectly handled the linuxbridge driver when ebtables-nft is being used. An attacker could possibly use this issue to impersonate the hardware address of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.