Improper Preservation of Permissions in containerd
CVE-2021-43816

8HIGH

Key Information:

Vendor

Containerd

Status
Containerd
Vendor
CVE Published:
5 January 2022

What is 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 Version(s)

containerd >= 1.5.0, < 1.5.9

References

https://github.com/containerd/containerd/security/advisor...
x_refsource_CONFIRM
https://github.com/containerd/containerd/issues/6194
x_refsource_MISC
https://github.com/containerd/containerd/commit/a73103923...
x_refsource_MISC

CVSS V3.1

Score:
8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
High
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.