CVE-2021-43816 Improper Preservation of Permissions in containerd

2022-01-0518:55:10

CWE-281

GitHub_M

www.cve.org

8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

9.2 High

AI Score

Confidence

High

0.005 Low

EPSS

Percentile

76.4%

JSON

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.

CNA Affected

[
  {
    "product": "containerd",
    "vendor": "containerd",
    "versions": [
      {
        "status": "affected",
        "version": ">= 1.5.0, < 1.5.9"
      }
    ]
  }
]