moby Access to remapped root allows privilege escalation to real root

中 6.8CVE-2021-21284 · GHSA-7452-xqpj-6rpc · 02/02/2021 公開 · 17/06/2026 更新

要点

CVE-2021-21284 は github.com/moby/moby, docker (docker), e-series santricity os controller (netapp) に影響する深刻度「中」 (CVSS 6.8) の脆弱性です。
今後30日間に悪用される確率（EPSS）：1.1%（全脆弱性の 65.0% より高い）。
対処：20.10.3, 19.3.15, 19.03.15 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/moby/moby Go	`≥ 20.10.0-beta1, < 20.10.3< 19.3.15`	`20.10.319.3.15`
docker docker	`≥ 20.0.0, < 20.10.3< 19.03.15`	`20.10.319.03.15`
e-series santricity os controller netapp	`≥ 11.0.0, ≤ 11.60.3`	修正版なし

概要

Impact

When using --userns-remap, if the root user in the remapped namespace has access to the host filesystem they can modify files under /var/lib/docker/<remapping> that cause writing files with extended privileges.

Patches

Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.

Credits

Maintainers would like to thank Alex Chapman for discovering the vulnerability; @awprice, @nathanburrell, @raulgomis, @chris-walz, @erin-jensby, @bassmatt, @mark-adams, @dbaxa for working on it and Zac Ellis for responsibly disclosing it to [email protected]

NVD の説明

In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.