How severe is CVE-2021-38598?

CVE-2021-38598 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2021-38598 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38598?

CVE-2021-38598 primarily affects Openstack Neutron. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38598?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-38598 published?

CVE-2021-38598 was published on 2021-08-23 and last updated on 2026-06-17.

CVE-2021-38598

CVE-2021-38598 is a critical-severity vulnerability in Openstack Neutron with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-290.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 5.8
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-290
Affected product: Openstack Neutron
Published: 2021-08-23
Last modified: 2026-06-17

Description

OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.

Frequently asked questions

What is CVE-2021-38598?: OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
How severe is CVE-2021-38598?: CVE-2021-38598 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2021-38598 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38598?: CVE-2021-38598 primarily affects Openstack Neutron. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38598?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-38598 published?: CVE-2021-38598 was published on 2021-08-23 and last updated on 2026-06-17.

References

https://launchpad.net/bugs/1938670

Affected products (2)

cpe:2.3:a:openstack:neutron:*:*:*:*:*:*:*:*
cpe:2.3:a:openstack:neutron:18.0.0:*:*:*:*:*:*:*

More vulnerabilities in Openstack Neutron

CVE-2015-8914 — Critical (CVSS 9.1): The IPTables firewall in OpenStack Neutron before 7.0.4 and 8.0.0 through 8.1.0 allows remote attackers to bypass an…
CVE-2014-0187 — Critical (CVSS 9.0): The openvswitch-agent process in OpenStack Neutron 2013.1 before 2013.2.4 and 2014.1 before 2014.1.1 allows remote…
CVE-2016-5363 — High (CVSS 8.2): The IPTables firewall in OpenStack Neutron before 7.0.4 and 8.0.0 through 8.1.0 allows remote attackers to bypass an…
CVE-2016-5362 — High (CVSS 8.2): The IPTables firewall in OpenStack Neutron before 7.0.4 and 8.0.0 through 8.1.0 allows remote attackers to bypass an…
CVE-2014-3632 — High (CVSS 7.6): The default configuration in a sudoers file in the Red Hat openstack-neutron package before 2014.1.2-4, as used in Red…
CVE-2013-6433 — High (CVSS 7.6): The default configuration in the Red Hat openstack-neutron package before 2013.2.3-7 does not properly set a…

All CVEs affecting Openstack Neutron →

Other CWE-290 vulnerabilities

CVE-2026-48567 — Critical (CVSS 10.0): Authentication bypass by spoofing in Azure HorizonDB allows an unauthorized attacker to elevate privileges over a…
CVE-2026-6213 — Critical (CVSS 10.0): A vulnerability in Remote Spark SparkView before build 1122 allows an attacker to bypasses the local connection check…
CVE-2026-39858 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high…
CVE-2025-66570 — Critical (CVSS 10.0): cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.27.0, a vulnerability…
CVE-2025-34063 — Critical (CVSS 10.0): A cryptographic authentication bypass vulnerability exists in OneLogin AD Connector prior to 6.1.5 due to the exposure…
CVE-2023-22814 — Critical (CVSS 10.0): An authentication bypass issue via spoofing was discovered in the token-based authentication mechanism that could allow…

Browse all CWE-290 vulnerabilities →