If /proc
and /sys
in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem.
For security reasons, container creation should be prohibited if /proc
or /sys
in the rootfs is a symbolic link.
I verified this behavior with youki
.
When /proc
or /sys
is a symbolic link, runc
fails to create the container, whereas youki
successfully creates it.
This is the fix related to this issue in runc
.
* https://github.com/opencontainers/runc/pull/3756
* https://github.com/opencontainers/runc/pull/3773
* https://github.com/opencontainers/runc/blob/main/libcontainer/rootfs_linux.go#L590
* https://github.com/opencontainers/runc/blob/main/tests/integration/mask.bats#L60
The following advisory appears to be related to this vulnerability: * https://github.com/advisories/GHSA-vpvm-3wq2-2wvm * https://github.com/advisories/GHSA-fh74-hm69-rqjw
{ "github_reviewed_at": "2025-08-14T16:39:04Z", "severity": "HIGH", "nvd_published_at": "2025-08-14T16:15:39Z", "github_reviewed": true, "cwe_ids": [ "CWE-61" ] }