CVE-2023-25809

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.