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High

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 impersonat

  • Disclosed: 28.05.2021
  • Updated: 11.10.2026 12:20

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.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (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

References

CVSS score 7.1/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
Weakness (CWE)
CWE-345
Platform
Python (PyPI)
Package
neutron
Disclosed
28.05.2021
Updated
11.10.2026 12:20

Sources and licenses

OSV / GitHub Advisory Database - GHSA-w8hx-f868-pvch - CC BY 4.0

OSV / GitHub Advisory Database - PYSEC-2021-136 - PyPA Advisory Database; CC BY 4.0

Vulnerability history: neutron

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (21) in the archive
Total entries
21
First → latest
09.2018 06.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 1
  • High 9
  • Medium 9
  • Low 2

Disclosures per year

Severity:
  1. OpenStack Neutron Intended MAC-spoofing protection mechanism bypass
    High · 8.2 CVE-2016-5363 < 7.1.0, >= 8.0.0, < 8.1.0 7.1.0, 8.1.0
  2. OpenStack Neutron allows remote attackers to bypass an intended DHCP-spoofing protection mechanism
    High · 8.2 CVE-2016-5362 < 7.0.5, >= 8.0.0, < 8.1.1 7.0.5, 8.1.1
  3. OpenStack Neutron allows remote attackers to bypass an intended ICMPv6-spoofing protection mechanism
    Critical · 9.1 CVE-2015-8914 < 7.0.5, >= 8.0.0, < 8.1.1 7.0.5, 8.1.1
  4. An issue was discovered in the routes middleware in OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1. By making API requests involving nonexistent controllers, an authentica
    High · 6.5 CVE-2021-40797 < 16.4.1, >= 17.0.0, < 17.2.1, >= 18.0.0, < 18.1.1 16.4.1, 17.2.1, 18.1.1
  5. An issue was discovered in OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1. Authenticated attackers can reconfigure dnsmasq via a crafted extra_dhcp_opts value.
    High · 6.5 CVE-2021-40085 < 16.4.1, >= 17.0.0, < 17.2.1, >= 18.0.0, < 18.1.1 16.4.1, 17.2.1, 18.1.1
  6. 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 ca
    High · 9.1 CVE-2021-38598 < 16.4.1, >= 17.0.0, < 17.1.3, >= 18.0.0, < 18.1.0 16.4.1, 17.1.3, 18.1.0
  7. 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 impersonat this entry
    High · 7.1 CVE-2021-20267 < 15.3.3, >= 16.0.0, < 16.3.1, >= 17.0.0, < 17.1.1 15.3.3, 16.3.1, 17.1.1
  8. An issue was discovered in OpenStack Neutron 11.x before 11.0.7, 12.x before 12.0.6, and 13.x before 13.0.3. By creating two security groups with separate/overlapping port ranges, an authenticated use
    High · 6.5 CVE-2019-10876 >= 12.0.0, < 12.0.6, < 11.0.7, >= 13.0.0, < 13.0.3 12.0.6, 11.0.7, 13.0.3
  9. An issue was discovered in the iptables firewall module in OpenStack Neutron before 10.0.8, 11.x before 11.0.7, 12.x before 12.0.6, and 13.x before 13.0.3. By setting a destination port in a security
    High · 6.5 CVE-2019-9735 >= 12.0.0, < 12.0.6, >= 13.0.0, < 13.0.3, >= 11.0.0, < 11.0.7, < 10.0.8 12.0.6, 13.0.3, 11.0.7, 10.0.8
  10. When using the Linux bridge ml2 driver, non-privileged tenants are able to create and attach ports without specifying an IP address, bypassing IP address validation. A potential denial of service coul
    High · 6.5 CVE-2018-14635 < 11.0.6, >= 12.0.0, < 12.0.4 11.0.6, 12.0.4

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