CVE-2021-43816

Improper Preservation of Permissions in containerd

At a glance

Severity
HIGH 8.0
EPSS
EPSS 1.68 % · percentile 77 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Modified

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

VersionScoreVectorScored by
CVSS 3.1HIGH 8.0CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:HGitHub_M
CVSS 3.1HIGH 8.0CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:HNVD · security-advisories@github.com (Secondary)
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HNVD · nvd@nist.gov (Primary)
CVSS 2.0MEDIUM 6.0AV:N/AC:M/Au:S/C:P/I:P/A:PNVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
containerd · containerdaffected >= 1.5.0, < 1.5.9

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD