CVE-2021-38598

Severity: critical (CVSS 9.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-08-23 · updated 2026-06-17
Weakness: CWE-290

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.

Affected products

OpenStack Neutron: before 16.4.1; from 17.0.0 before 17.1.3; 18.0.0 — fixed in 16.4.1, 17.1.3

How to fix

Upgrade to a fixed version: OpenStack Neutron 16.4.1, 17.1.3. Check the vendor advisory for mitigations.

References

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