CVE-2021-20267

HighCVSS 7.1/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 7.1/10CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

Weakness enumeration

CWE-345

Affected software

VendorProductVersions
n/aopenstack-neutronopenstack-neutron 15.3.3, openstack-neutron 16.3.1, openstack-neutron 17.1.1

References

Timeline

Published
May 28, 2021
Last modified
Jun 17, 2026
NVD status
Modified

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CVE-2021-20267: High severity, CVSS 7.1 | Vulnix