podman-container-tools/buildah

A flaw was found in Buildah (and subsequently Podman Build) which allows containers to mount arbitrary locations on the host filesystem into build containers. A malicious Containerfile can use a dummy image with a symbolic link to the root filesystem as a mount source and cause the mount operation to mount the host root filesystem inside the RUN step. The commands inside the RUN step will then have read-write access to the host filesystem, allowing for full container escape at build time.

A flaw was found in buildah where containers were incorrectly started with non-empty default permissions. A bug was found in Moby (Docker Engine) where containers were incorrectly started with non-empty inheritable Linux process capabilities, enabling an attacker with access to programs with inheritable file capabilities to elevate those capabilities to the permitted set when execve(2) runs. This has the potential to impact confidentiality and integrity.

An information disclosure flaw was found in Buildah, when building containers using chroot isolation. Running processes in container builds (e.g. Dockerfile RUN commands) can access environment variables from parent and grandparent processes. When run in a container in a CI/CD environment, environment variables may include sensitive information that was shared with the container in order to be used only by Buildah itself (e.g. container registry credentials).

A path traversal flaw was found in Buildah in versions before 1.14.5. This flaw allows an attacker to trick a user into building a malicious container image hosted on an HTTP(s) server and then write files to the user's system anywhere that the user has permissions.