CVSS 3.1
7.1 highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:HCVE-2021-20267
High (7.1). EPSS 1.0% chance of exploitation in the next 30 days. Fixed in neutron 15.3.3, 16.3.1, 17.1.1.
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.
Severity
- EPSS
- 1.0% chance of exploitation in the next 30 days; higher than 63% of CVEs (scores of 2026-10-31)
- CWE
- CWE-345
- Published
- Modified
- Record from
- the NVD, synced
Affected
- openstack:neutron
- redhat:openstack_platform
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w8hx-f868-pvch | PyPI | neutron | >=16.0.0 <16.3.1 | 16.3.1 |
| GHSA-w8hx-f868-pvch | PyPI | neutron | <15.3.3 | 15.3.3 |
| GHSA-w8hx-f868-pvch | PyPI | neutron | >=17.0.0 <17.1.1 | 17.1.1 |
| PYSEC-2021-136 | PyPI | neutron | <15.3.3 >=16.0.0 <16.3.1 >=17.0.0 <17.1.1 | 15.3.3, 16.3.1, 17.1.1 |