OSSA-2021-001: Anti-spoofing bypass for Open vSwitch networks

Date:

July 12, 2021

CVE:

CVE-2021-20267

Affects

• Neutron: <16.3.3, >=17.0.0 <17.1.3, =18.0.0

Description

David Sinquin with Gandi.net reported a vulnerability in 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.

Patches

• https://review.opendev.org/777873 (Queens)

• https://review.opendev.org/791470 (Queens)

• https://review.opendev.org/777786 (Rocky)

• https://review.opendev.org/791469 (Rocky)

• https://review.opendev.org/777872 (Stein)

• https://review.opendev.org/791500 (Stein)

• https://review.opendev.org/777785 (Train)

• https://review.opendev.org/791468 (Train)

• https://review.opendev.org/777784 (Ussuri)

• https://review.opendev.org/791467 (Ussuri)

• https://review.opendev.org/777783 (Victoria)

• https://review.opendev.org/791465 (Victoria)

• https://review.opendev.org/776599 (Wallaby)

• https://review.opendev.org/791464 (Wallaby)

• https://review.opendev.org/783743 (Xena)

Credits

• David Sinquin from Gandi.net (CVE-2021-20267)

References

• https://launchpad.net/bugs/1902917

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20267

Notes

• The stable/train, stable/stein, stable/rocky, and stable/queens branches are under extended maintenance and will receive no new point releases, but patches for them are provided as a courtesy.