A vulnerability was found in Podman, Buildah, and CRI-O. A symlink traversal vulnerability in the containers/storage library can cause Podman, Buildah, and CRI-O to hang and result in a denial of service via OOM kill when running a malicious image using an automatically assigned user namespace (`--userns=auto` in Podman and Buildah). The containers/storage library will read /etc/passwd inside the container, but does not properly validate if that file is a symlink, which can be used to cause the library to read an arbitrary file on the host.
Workaround:
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.