ghsa-mvff-h3cj-wj9c
Vulnerability from github
Impact
Containers launched through containerd’s CRI implementation on Linux systems which use the SELinux security module and containerd versions since v1.5.0 can cause arbitrary files and directories on the host to be relabeled to match the container process label through the use of specially-configured bind mounts in a hostPath volume. This relabeling elevates permissions for the container, granting full read/write access over the affected files and directories. Kubernetes and crictl can both be configured to use containerd’s CRI implementation.
If you are not using containerd’s CRI implementation (through one of the mechanisms described above), you are not affected by this issue.
Patches
This bug has been fixed in containerd 1.5.9. Because file labels persist independently of containerd, users should both update to these versions as soon as they are released and validate that all files on their host are correctly labeled.
Workarounds
Ensure that no sensitive files or directories are used as a hostPath volume source location. Policy enforcement mechanisms such a Kubernetes Pod Security Policy AllowedHostPaths may be specified to limit the files and directories that can be bind-mounted to containers.
For more information
If you have any questions or comments about this advisory:
- Open an issue in containerd
- Email us at security@containerd.io
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/containerd/containerd"
},
"ranges": [
{
"events": [
{
"introduced": "1.5.0"
},
{
"fixed": "1.5.9"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-43816"
],
"database_specific": {
"cwe_ids": [
"CWE-281"
],
"github_reviewed": true,
"github_reviewed_at": "2022-01-05T21:09:16Z",
"nvd_published_at": "2022-01-05T19:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\n\nContainers launched through containerd\u2019s CRI implementation on Linux systems which use the SELinux security module and containerd versions since v1.5.0 can cause arbitrary files and directories on the host to be relabeled to match the container process label through the use of specially-configured bind mounts in a hostPath volume. This relabeling elevates permissions for the container, granting full read/write access over the affected files and directories. Kubernetes and crictl can both be configured to use containerd\u2019s CRI implementation.\n\nIf you are not using containerd\u2019s CRI implementation (through one of the mechanisms described above), you are not affected by this issue.\n\n### Patches\n\nThis bug has been fixed in containerd 1.5.9. Because file labels persist independently of containerd, users should both update to these versions as soon as they are released and validate that all files on their host are correctly labeled.\n\n### Workarounds\n\nEnsure that no sensitive files or directories are used as a hostPath volume source location. Policy enforcement mechanisms such a Kubernetes Pod Security Policy [AllowedHostPaths](https://kubernetes.io/docs/concepts/policy/pod-security-policy/#volumes-and-file-systems) may be specified to limit the files and directories that can be bind-mounted to containers.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* Open an issue in [containerd](https://github.com/containerd/containerd/issues/new/choose)\n* Email us at [security@containerd.io](mailto:security@containerd.io)",
"id": "GHSA-mvff-h3cj-wj9c",
"modified": "2022-04-04T20:40:33Z",
"published": "2022-01-06T17:36:59Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/containerd/containerd/security/advisories/GHSA-mvff-h3cj-wj9c"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-43816"
},
{
"type": "WEB",
"url": "https://github.com/containerd/containerd/issues/6194"
},
{
"type": "WEB",
"url": "https://github.com/containerd/containerd/commit/a731039238c62be081eb8c31525b988415745eea"
},
{
"type": "WEB",
"url": "https://github.com/dweomer/containerd/commit/f7f08f0e34fb97392b0d382e58916d6865100299"
},
{
"type": "PACKAGE",
"url": "https://github.com/containerd/containerd"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GD5GH7NMK5VJMA2Y5CYB5O5GTPYMWMLX"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MPDIZMI7ZPERSZE2XO265UCK5IWM7CID"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Unprivileged pod using `hostPath` can side-step active LSM when it is SELinux"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.