Youki: If /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem.
### Summary If `/proc` and `/sys` in the rootfs are symbolic links, they can potentially be exploited to gain access to the host root filesystem. ### Details 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 ### Impact 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
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-54867US | — | — | ||
Youki is a container runtime written in Rust. Prior to version 0.5.5, if /proc and /sys in the rootfs are symbolic links, they can potentially be exploited to gain access to the ho… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/youki-dev/youkiPACKAGE
- https://github.com/youki-dev/youki/commit/0d9b4f2aa5ceaf988f3eb568711d2acf0a4ace37WEB
- https://github.com/youki-dev/youki/releases/tag/v0.5.5WEB
- https://github.com/youki-dev/youki/security/advisories/GHSA-j26p-6wx7-f3pwWEB
- https://nvd.nist.gov/vuln/detail/CVE-2025-54867ADVISORY
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