CVE-2025-62596

Youki is a container runtime written in Rust. In versions 0.5.6 and below, youki’s apparmor handling performs insufficiently strict write-target validation, and when combined with path substitution during pathname resolution, can allow writes to unintended procfs locations. While resolving a path component-by-component, a shared-mount race can substitute intermediate components and redirect the final target. This issue is fixed in version 0.5.7.

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.

Affected Software

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/5886c91073b9be748bd8d5aed49c4a820548030a
• https://github.com/youki-dev/youki/security/advisories/GHSA-vf95-55w6-qmrf
• https://pkg.go.dev/github.com/cyphar/filepath-securejoin/pathrs-lite/procfs
• https://youtu.be/tGseJW_uBB8
• https://youtu.be/y1PaBzxwRWQ