CVE-2025-54867

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 host root filesystem. This issue has been patched in version 0.5.5.

Weakness

The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/27.html

References

• https://github.com/youki-dev/youki/commit/0d9b4f2aa5ceaf988f3eb568711d2acf0a4ace37
• https://github.com/youki-dev/youki/releases/tag/v0.5.5
• https://github.com/youki-dev/youki/security/advisories/GHSA-j26p-6wx7-f3pw