Insufficiently restricted permissions on plugin directories

高 7.8CVE-2021-41103 · GHSA-c2h3-6mxw-7mvq · GO-2022-0938 · 04/10/2021 公開 · 17/06/2026 更新

要点

CVE-2021-41103 は github.com/containerd/containerd, containerd (linuxfoundation) に影響する深刻度「高」 (CVSS 7.8) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.52%（全脆弱性の 44.1% より高い）。
対処：1.5.7, 1.4.11 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
github.com/containerd/containerd Go	`≥ 1.5.0, < 1.5.7< 1.4.11`	`1.5.71.4.11`
containerd linuxfoundation	`≥ 1.5.0, < 1.5.7< 1.4.11`	`1.5.71.4.11`

概要

Impact

A bug was found in containerd where container root directories and some plugins had insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as setuid), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files.

Patches

This vulnerability has been fixed in containerd 1.4.11 and containerd 1.5.7. Users should update to these version when they are released and may restart containers or update directory permissions to mitigate the vulnerability.

Workarounds

Limit access to the host to trusted users. Update directory permission on container bundles directories.

For more information

If you have any questions or comments about this advisory:

Open an issue in github.com/containerd/containerd
Email us at [email protected]

NVD の説明

containerd is an open source container runtime with an emphasis on simplicity, robustness and portability. A bug was found in containerd where container root directories and some plugins had insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as setuid), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files. This vulnerability has been fixed in containerd 1.4.11 and containerd 1.5.7. Users should update to these version when they are released and may restart containers or update directory permissions to mitigate the vulnerability. Users unable to update should limit access to the host to trusted users. Update directory permission on container bundles directories.