CVE-2021-43816

HIGH

containerd <1.5.0-beta.0 - Info Disclosure

Title source: llm
STIX 2.1

Description

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.

Scores

CVSS v3 8.0
EPSS 0.0015
EPSS Percentile 34.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-281
Status published
Products (5)
containerd/containerd 1.5.0 - 1.5.9Go
fedoraproject/fedora 34
fedoraproject/fedora 35
linuxfoundation/containerd 1.5.0 (10 CPE variants)
linuxfoundation/containerd 1.5.1 - 1.5.9
Published Jan 05, 2022
Tracked Since Feb 18, 2026