CVE-2020-15257 log

Source	CVE Red Hat MITRE NVD Debian Ubuntu SUSE Alpine Mageia CVE Details CIRCL Bugs Arch Linux Red Hat Gentoo SUSE GitHub Lists oss-security full-disclosure bugtraq Misc GitHub code web search
Severity	High
Remote	No
Type	Privilege escalation
Description	In containerd before versions 1.3.9 and 1.4.3, the containerd-shim API is improperly exposed to host network containers. Access controls for the shim's API socket verified that the connecting process had an effective UID of 0, but did not otherwise restrict access to the abstract Unix domain socket. This would allow malicious containers running in the same network namespace as the shim, with an effective UID of 0 but otherwise reduced privileges, to cause new processes to be run with elevated privileges. It should be noted that containers started with an old version of containerd-shim should be stopped and restarted, as running containers will continue to be vulnerable even after an upgrade.

Group	Package	Affected	Fixed	Severity	Status	Ticket
AVG-1309	containerd	1.4.2-2	1.4.3-1	High	Fixed

Date	Advisory	Group	Package	Severity	Type
05 Dec 2020	ASA-202012-8	AVG-1309	containerd	High	privilege escalation

References
https://github.com/containerd/containerd/security/advisories/GHSA-36xw-fx78-c5r4 https://github.com/containerd/containerd/commit/428f10fd27eb1f9bd0b9aaa33a6579416c3a8b12 https://github.com/containerd/containerd/commit/ae3a64aa10d6d9b1567adce057778800c9cc45ed

References

https://github.com/containerd/containerd/security/advisories/GHSA-36xw-fx78-c5r4
https://github.com/containerd/containerd/commit/428f10fd27eb1f9bd0b9aaa33a6579416c3a8b12
https://github.com/containerd/containerd/commit/ae3a64aa10d6d9b1567adce057778800c9cc45ed

Notes
Workaround ========== If you are not providing the ability for untrusted users to start containers in the same network namespace as the shim (typically the "host" network namespace, for example with docker run --net=host or hostNetwork: true in a Kubernetes pod) and run with an effective UID of 0, you are not vulnerable to this issue. If you are running containers with a vulnerable configuration, you can deny access to all abstract sockets with AppArmor by adding a line similar to deny unix addr=@**, to your policy. It is best practice to run containers with a reduced set of privileges, with a non-zero UID, and with isolated namespaces. The containerd maintainers strongly advise against sharing namespaces with the host. Reducing the set of isolation mechanisms used for a container necessarily increases that container's privilege, regardless of what container runtime is used for running that container.

Notes

Workaround
==========

If you are not providing the ability for untrusted users to start containers in the same network namespace as the shim (typically the "host" network namespace, for example with docker run --net=host or hostNetwork: true in a Kubernetes pod) and run with an effective UID of 0, you are not vulnerable to this issue.

If you are running containers with a vulnerable configuration, you can deny access to all abstract sockets with AppArmor by adding a line similar to deny unix addr=@**, to your policy.

It is best practice to run containers with a reduced set of privileges, with a non-zero UID, and with isolated namespaces. The containerd maintainers strongly advise against sharing namespaces with the host. Reducing the set of isolation mechanisms used for a container necessarily increases that container's privilege, regardless of what container runtime is used for running that container.