Insufficient verification of data authenticity in openstack-neutron
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-345.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | openstack-neutron | openstack-neutron 15.3.3, openstack-neutron 16.3.1, openstack-neutron 17.1.1 | — | No fix listed | CNA |
| — | neutron (PyPI) | 16.0.0 to before 16.3.1 | 16.3.1 | Patch available | GHSA-w8hx-f868-pvch |
| — | neutron (PyPI) | before 15.3.3 | 15.3.3 | Patch available | GHSA-w8hx-f868-pvch |
| — | neutron (PyPI) | 17.0.0 to before 17.1.1 | 17.1.1 | Patch available | GHSA-w8hx-f868-pvch |
- openstack-neutron Vendor— Affected openstack-neutron 15.3.3, openstack-neutron 16.3.1, openstack-neutron 17.1.1 Fixed in — No fix listed CNA
- neutron (PyPI) Vendor— Affected 16.0.0 to before 16.3.1 Fixed in 16.3.1 Patch available GHSA-w8hx-f868-pvch
- neutron (PyPI) Vendor— Affected before 15.3.3 Fixed in 15.3.3 Patch available GHSA-w8hx-f868-pvch
- neutron (PyPI) Vendor— Affected 17.0.0 to before 17.1.1 Fixed in 17.1.1 Patch available GHSA-w8hx-f868-pvch
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:openstack:neutron:*:*:*:*:*:*:*:* | before 16.3.3; 17.0.0 to before 17.1.3 | Vulnerable | OpenStack |
| cpe:2.3:a:openstack:neutron:18.0.0:*:*:*:*:*:*:* | 18.0.0 | Vulnerable | OpenStack |
| cpe:2.3:a:redhat:openstack_platform:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:openstack_platform:13.0:*:*:*:*:*:*:* | 13.0 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:openstack_platform:16.1:*:*:*:*:*:*:* | 16.1 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:openstack_platform:16.2:*:*:*:*:*:*:* | 16.2 | Vulnerable | Red Hat |
- cpe:2.3:a:openstack:neutron:*:*:*:*:*:*:*:* Versions before 16.3.3; 17.0.0 to before 17.1.3 Vulnerable ·OpenStack
- cpe:2.3:a:openstack:neutron:18.0.0:*:*:*:*:*:*:* Versions 18.0.0 Vulnerable ·OpenStack
- cpe:2.3:a:redhat:openstack_platform:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:openstack_platform:13.0:*:*:*:*:*:*:* Versions 13.0 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:openstack_platform:16.1:*:*:*:*:*:*:* Versions 16.1 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:openstack_platform:16.2:*:*:*:*:*:*:* Versions 16.2 Vulnerable ·Red Hat
Remediation
- Fix · GHSA-w8hx-f868-pvch neutron (PyPI) Fixed in 16.3.1 Advisory →
- Fix · GHSA-w8hx-f868-pvch neutron (PyPI) Fixed in 15.3.3 Advisory →
- Fix · GHSA-w8hx-f868-pvch neutron (PyPI) Fixed in 17.1.1 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenStack Platform 10 (Newton) | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 13 (Queens) | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 16.1 | Affected | No fix yet: Fix deferred |
| Red Hat OpenStack Platform 16.2 | Affected | No fix planned: Out of support scope |
| Red Hat OpenStack Platform 17.1 | Affected | No fix planned: Out of support scope |
Not affected: 1 product
- Red Hat OpenStack Platform 18.0
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20267
- 2026-10-03 Alias added: GHSA-w8hx-f868-pvch
- 2026-10-07 Affected versions changed · Red Hat
- 2026-10-08 Affected versions changed · Red Hat
References
Sources
- CVE-2021-20267 · CVE Program
- CVE-2021-20267 · NVD
- FIRST EPSS
- GHSA-w8hx-f868-pvch · GitHub Advisory Database · CC BY 4.0
- CVE-2021-20267 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences