Описание
Moby firewalld reload makes published container ports accessible from remote hosts
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker Engine, Mirantis Container Runtime, and various other downstream projects/products. The Moby daemon component (dockerd), which is developed as moby/moby is commonly referred to as Docker, or Docker Engine.
Firewalld is a daemon used by some Linux distributions to provide a dynamically managed firewall. When Firewalld is running, Docker uses its iptables backend to create rules, including rules to isolate containers in one bridge network from containers in other bridge networks.
Impact
The iptables rules created by Docker are removed when firewalld is reloaded using, for example "firewall-cmd --reload", "killall -HUP firewalld", or "systemctl reload firewalld".
When that happens, Docker must re-create the rules. However, in affected versions of Docker, the iptables rules that prevent packets arriving on a host interface from reaching container addresses are not re-created.
Once these rules have been removed, a remote host configured with a route to a Docker bridge network can access published ports, even when those ports were only published to a loopback address. Unpublished ports remain inaccessible.
For example, following a firewalld reload on a Docker host with address 192.168.0.10 and a bridge network with subnet 172.17.0.0/16, running the following command on another host in the local network will give it access to published ports on container addresses in that network: ip route add 172.17.0.0/16 via 192.168.0.10.
Containers running in networks created with --internal or equivalent have no access to other networks. Containers that are only connected to these networks remain isolated after a firewalld reload.
Where Docker Engine is not running in the host's network namespace, it is unaffected. Including, for example, Rootless Mode, and Docker Desktop.
Patches
Moby releases older than 28.2.0 are not affected. A fix is available in moby release 28.3.3.
Workarounds
After reloading firewalld, either:
- Restart the docker daemon,
- Re-create bridge networks, or
- Use rootless mode.
References
https://firewalld.org/ https://firewalld.org/documentation/howto/reload-firewalld.html
Пакеты
github.com/docker/docker
>= 28.2.0, < 28.3.3
28.3.3
Связанные уязвимости
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker Engine, Mirantis Container Runtime, and various other downstream projects/products. In versions 28.2.0 through 28.3.2, when the firewalld service is reloaded it removes all iptables rules including those created by Docker. While Docker should automatically recreate these rules, versions before 28.3.3 fail to recreate the specific rules that block external access to containers. This means that after a firewalld reload, containers with ports published to localhost (like 127.0.0.1:8080) become accessible from remote machines that have network routing to the Docker bridge, even though they should only be accessible from the host itself. The vulnerability only affects explicitly published ports - unpublished ports remain protected. This issue is fixed in version 28.3.3.
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker Engine, Mirantis Container Runtime, and various other downstream projects/products. In versions 28.2.0 through 28.3.2, when the firewalld service is reloaded it removes all iptables rules including those created by Docker. While Docker should automatically recreate these rules, versions before 28.3.3 fail to recreate the specific rules that block external access to containers. This means that after a firewalld reload, containers with ports published to localhost (like 127.0.0.1:8080) become accessible from remote machines that have network routing to the Docker bridge, even though they should only be accessible from the host itself. The vulnerability only affects explicitly published ports - unpublished ports remain protected. This issue is fixed in version 28.3.3.
Moby is an open source container framework developed by Docker Inc. that is distributed as Docker Engine, Mirantis Container Runtime, and various other downstream projects/products. In versions 28.2.0 through 28.3.2, when the firewalld service is reloaded it removes all iptables rules including those created by Docker. While Docker should automatically recreate these rules, versions before 28.3.3 fail to recreate the specific rules that block external access to containers. This means that after a firewalld reload, containers with ports published to localhost (like 127.0.0.1:8080) become accessible from remote machines that have network routing to the Docker bridge, even though they should only be accessible from the host itself. The vulnerability only affects explicitly published ports - unpublished ports remain protected. This issue is fixed in version 28.3.3.
Moby is an open source container framework developed by Docker Inc. th ...
Уязвимость демона firewalld программного средства для создания систем контейнерной изоляции Moby, позволяющая нарушителю получить несанкционированный доступ к защищаемой информации