CVE-2025-27612

libcontainer is a library for container control. Prior to libcontainer 0.5.3, while creating a tenant container, the tenant builder accepts a list of capabilities to be added in the spec of tenant container. The logic here adds the given capabilities to all capabilities of main container if present in spec, otherwise simply set provided capabilities as capabilities of the tenant container. However, setting inherited caps in any case for tenant container can lead to elevation of capabilities, similar to CVE-2022-29162. This does not affect youki binary itself. This is only applicable if you are using libcontainer directly and using the tenant builder.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://github.com/opencontainers/runc/security/advisories/GHSA-f3fp-gc8g-vw66
• https://github.com/youki-dev/youki/blob/9e63fa4da1672a78ca45100f3059a732784a5174/crates/libcontainer/src/container/tenant_builder.rs#L408
• https://github.com/youki-dev/youki/commit/747e342d2026fbf3a395db3e2a491ebef00082f1
• https://github.com/youki-dev/youki/security/advisories/GHSA-5w4j-f78p-4wh9