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CVE-2021-20267

Publication date 28 May 2021

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.1 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
neutron 24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.10 kinetic
Not affected
22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute Ignored end of life
20.10 groovy Ignored end of life
20.04 LTS focal
Fixed 2:16.4.2-0ubuntu6.2
18.04 LTS bionic
Fixed 2:12.1.1-0ubuntu8.1
16.04 LTS xenial
Vulnerable
14.04 LTS trusty Not in release

Notes

mdeslaur

per upstream Affects: <15.3.3, >=16.0.0 <16.3.1, >=17.0.0 <17.1.1 as of 2021-05-13, patch has been flagged as possibly incomplete see comment #17 in upstream bug. addditional patch: https://review.opendev.org/c/openstack/neutron/+/783743 This issue was fixed in (2:16.4.0-0ubuntu2) in focal-updates and (2:18.1.0-0ubuntu2) in hirsute-updates, and was later released to -security.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
neutron

Severity score breakdown

Parameter Value
Base score 7.1 · High
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality Low
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-6067-1
    • OpenStack Neutron vulnerabilities
    • 10 May 2023

Other references