CVE-2021-43816

containerd is an open source container runtime. On installations using SELinux, such as EL8 (CentOS, RHEL), Fedora, or SUSE MicroOS, with containerd since v1.5.0-beta.0 as the backing container runtime interface (CRI), an unprivileged pod scheduled to the node may bind mount, via hostPath volume, any privileged, regular file on disk for complete read/write access (sans delete). Such is achieved by placing the in-container location of the hostPath volume mount at either `/etc/hosts`, `/etc/hostname`, or `/etc/resolv.conf`. These locations are being relabeled indiscriminately to match the container process-label which effectively elevates permissions for savvy containers that would not normally be able to access privileged host files. This issue has been resolved in version 1.5.9. Users are advised to upgrade as soon as possible.

Affected products

Alt Linux, Kubernetes Containerd

Linuxfoundation Containerd

< 1.5.9, 1.5.0

Fix

Available

CVSS 3.1

9.1 CRITICAL

EPSS

1.7% (75th percentile)

Weakness

CWE-281

NVD status

Modified

Published

2022-01-05

No exploit for CVE-2021-43816 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.