Vulnerability Monitor

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CVE-2021-20267


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.


Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 7.1, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts limited data confidentiality, and availability (service disruption) for affected systems. Impacting 2 products from openstack, from redhat organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-05-28T19:15:07.483

Last Modified

2024-11-21T05:46:14.713

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 7.1 (HIGH)

CVSSv2 Vector

AV:N/AC:L/Au:S/C:P/I:N/A:P

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: SINGLE
  • Confidentiality Impact: PARTIAL
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

8.0

Impact Score

4.9

Weaknesses
  • Type: Secondary
    CWE-345

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application openstack neutron < 16.3.3 Yes
Application openstack neutron < 17.1.3 Yes
Application openstack neutron 18.0.0 Yes
Application redhat openstack_platform 10.0 Yes
Application redhat openstack_platform 13.0 Yes
Application redhat openstack_platform 16.1 Yes
Application redhat openstack_platform 16.2 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For openstack's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.