VULNERABILITY INTELLIGENCE

CVE-2021-20267

CVSS score7.1 HIGH

EPSS probability1.02%

CISA KEVNot currently listed

Published2021-05-28

Last modified2026-06-17

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

Description

A flaw was found in openstack-neutron's default Open vSwitch firewall rules. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the IPv6 addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations. Only deployments using the Open vSwitch driver are affected. Source: OpenStack project. Versions before openstack-neutron 15.3.3, openstack-neutron 16.3.1 and openstack-neutron 17.1.1 are affected.

Weakness classification

secalert@redhat.com: CWE-345

Primary references

secalert@redhat.com — Issue Tracking, Patch, Third Party Advisory
secalert@redhat.com — Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Patch, Vendor Advisory