CVE-2021-20267

2021-05-2800:00:00

ubuntu.com

5.5 Medium

CVSS2

Attack Vector

NETWORK

Attack Complexity

LOW

Authentication

SINGLE

Confidentiality Impact

PARTIAL

Integrity Impact

NONE

Availability Impact

PARTIAL

AV:N/AC:L/Au:S/C:P/I:N/A:P

7.1 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

NONE

Availability Impact

HIGH

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

0.001 Low

EPSS

Percentile

30.0%

JSON

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.

Bugs

<https://bugs.launchpad.net/neutron/+bug/1902917>

Notes

Author	Note
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.

OSVersionArchitecturePackageVersionFilename
ubuntu18.04noarchneutron< 2:12.1.1-0ubuntu8.1UNKNOWN
ubuntu20.04noarchneutron< 2:16.4.2-0ubuntu6.2UNKNOWN
ubuntu16.04noarchneutron< anyUNKNOWN