CVE-2021-20267

Name	CVE-2021-20267
Description	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	985104

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
neutron (PTS)	bullseye (security), bullseye	2:17.2.1-0+deb11u1	fixed
	bookworm	2:21.0.0-7	fixed
	trixie	2:25.0.0-3	fixed
	sid	2:25.0.0-4	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
neutron	source	buster	2:13.0.7+git.2021.09.27.bace3d1890-0+deb10u1
neutron	source	(unstable)	2:17.1.1-5			985104

Notes

[stretch] - neutron <ignored> (Minor issue; requires non-trivial backport)
https://bugs.launchpad.net/neutron/+bug/1902917
https://review.opendev.org/c/openstack/neutron/+/776599
Followup: https://review.opendev.org/c/openstack/neutron/+/783743
https://www.openwall.com/lists/oss-security/2021/07/12/2