CVE-2021-40085 OpenStack Neutron vulnerable to authenticated attackers reconfiguring dnsmasq via crafted extra_dhcp_opts value

Medium 6.5 Published Updated

Authenticated attackers can execute arbitrary commands by injecting malicious values into DHCP options, potentially compromising the network infrastructure.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2021-40085?

CVE-2021-40085 is a medium-severity command injection vulnerability in Debian Debian Linux, published on 31 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Which versions are affected by CVE-2021-40085?

7 open source packages ship an affected version, including neutron. It affects 2 products.

PackageAffectedFixed in
neutron PyPIAll versions16.4.1, 17.2.1, 18.1.1
neutron PyPIAll versions16.4.1
neutron PyPIAll versions16.4.1
neutron PyPIFrom 17.0.017.2.1
neutron PyPIFrom 17.0.017.2.1
neutron PyPIFrom 18.0.018.1.1
1 more packages
neutron PyPIFrom 18.0.018.1.1
Linux distribution packages (33)
openstack-neutron Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-common Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-linuxbridge Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-macvtap-agent Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-metering-agent Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-ml2 Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-openvswitch Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-rpc-server Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron-sriov-nic-agent Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
python-neutron Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
python-neutron-tests Red Hat:openstack:10::el7All versions1:9.4.1-56.el7ost
openstack-neutron Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-common Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-linuxbridge Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-macvtap-agent Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-metering-agent Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-ml2 Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-openvswitch Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-rpc-server Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron-sriov-nic-agent Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
python-neutron Red Hat:openstack:13::el7All versions1:12.1.1-42.1.el7ost
openstack-neutron Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-common Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-linuxbridge Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-macvtap-agent Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-metering-agent Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-ml2 Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-openvswitch Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-rpc-server Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron-sriov-nic-agent Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
python3-neutron Red Hat:openstack:16.1::el8All versions1:15.2.1-1.20210409073447.el8ost
openstack-neutron Red Hat:openstack:16.2::el8All versions1:15.3.5-2.20210608154813.el8ost.3
openstack-neutron-common Red Hat:openstack:16.2::el8All versions1:15.3.5-2.20210608154813.el8ost.3

Products include Debian Debian Linux, Openstack Neutron.

How do I fix CVE-2021-40085?

Upgrade neutron to a fixed version for your release line: 16.4.1, 17.2.1 or 18.1.1.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2021-40085 being exploited?

There is no known exploitation of CVE-2021-40085 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as DEBIAN-CVE-2021-40085, DLA-3027-1, DSA-4983-1, GHSA-fh73-gjvg-349c, PYSEC-2021-361, RHSA-2021:3481 and 4 more.

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