CVE-2021-43816: Improper Preservation of Permissions
(updated )
containerd is an open source container runtime. On installations using SELinux, such as EL8 (CentOS, RHEL), Fedora, or SUSE MicroOS, with containerd 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 Users are advised to upgrade as soon as possible.
References
- github.com/containerd/containerd/commit/a731039238c62be081eb8c31525b988415745eea
- github.com/containerd/containerd/issues/6194
- github.com/containerd/containerd/security/advisories/GHSA-mvff-h3cj-wj9c
- github.com/dweomer/containerd/commit/f7f08f0e34fb97392b0d382e58916d6865100299
- nvd.nist.gov/vuln/detail/CVE-2021-43816
Detect and mitigate CVE-2021-43816 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →