Is CVE-2021-20267 in the CISA KEV catalog?

No. CVE-2021-20267 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-20267?

CVE-2021-20267 has a CVSS v3 base score of 7.1 (HIGH).

What is the EPSS score for CVE-2021-20267?

CVE-2021-20267 has an EPSS score of 1.01% (59th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-20267?

Upgrade neutron on debian 11 to 2:17.1.1-5 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2021-20267

HIGH

7.1

CVSS v3

NVD

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.

CWE-345

How to fix

Remediation Available

neutronDebian

Fixed in:2:17.1.1-5CVE-2021-20267

neutronUbuntu

Fixed in:2:12.1.1-0ubuntu8.1USN-6067-1

Fixed in:2:16.4.2-0ubuntu6.2USN-6067-1

Fixed in:2:20.3.0-0ubuntu1.1USN-6067-1

python-neutronUbuntu

Fixed in:2:12.1.1-0ubuntu8.1USN-6067-1

python3-neutronUbuntu

Fixed in:2:16.4.2-0ubuntu6.2USN-6067-1

Fixed in:2:20.3.0-0ubuntu1.1USN-6067-1

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

1.01%probability of exploitation in 30 days

59thpercentile

Moderate risk: more likely to be exploited than 59% of all known CVEs.

References

Patch2

Related Vulnerabilities

Other CWE-345 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-38831	High	7.8	98%	KEV + Ransom	Fix
CVE-2016-4553	High	8.6	80%	-	Fix
CVE-2016-4554	High	8.6	39%	-	Fix
CVE-2023-35719	Medium	6.8	26%	-	-
CVE-2022-26871	Critical	9.8	20%	KEV	-
CVE-2014-4936	High	9.3	17%	-	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.