CVE-2021-20267

HIGH
7.1
CVSS Score
Published: May 28, 2021 at 06:46 PM UTC
Updated: June 17, 2026 at 03:33 AM UTC
2 products affected across 2 vendorsOpenStack PlatformNeutron

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Severity
HIGH7.1
Exploit prediction
EPSS 1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Affected range stops below 16.3.3, so it looks safe — our inference, not a vendor statement
Affected range stops below 17.1.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_MISCIssue TrackingPatchThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1934330

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-345

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