Public on 2023-03-29
Modified on 2023-03-30
runc is a CLI tool for spawning and running containers according to the OCI specification. In affected versions it was found that rootless runc makes `/sys/fs/cgroup` writable in following conditons: 1. when runc is executed inside the user namespace, and the `config.json` does not specify the cgroup namespace to be unshared (e.g.., `(docker|podman|nerdctl) run --cgroupns=host`, with Rootless Docker/Podman/nerdctl) or 2. when runc is executed outside the user namespace, and `/sys` is mounted with `rbind, ro` (e.g., `runc spec --rootless`; this condition is very rare). A container may gain the write access to user-owned cgroup hierarchy `/sys/fs/cgroup/user.slice/...` on the host . Other users's cgroup hierarchies are not affected. Users are advised to upgrade to version 1.1.5. Users unable to upgrade may unshare the cgroup namespace (`(docker|podman|nerdctl) run --cgroupns=private)`. This is the default behavior of Docker/Podman/nerdctl on cgroup v2 hosts. or add `/sys/fs/cgroup` to `maskedPaths`.
Low severity
CVSS v3 Base Score
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 1 runc Pending Fix
Amazon Linux 2 - Docker Extra runc 2023-05-25 ALAS2DOCKER-2023-025 Fixed
Amazon Linux 2 - Ecs Extra runc 2023-05-25 ALAS2ECS-2023-004 Fixed
Amazon Linux 2 - Aws-nitro-enclaves-cli Extra runc 2023-05-25 ALAS2NITRO-ENCLAVES-2023-024 Fixed
Amazon Linux 2023 runc 2023-06-07 ALAS2023-2023-208 Fixed

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 2.5 CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:L