    def _untarzip_image(path, filename):
        S3ImageService._test_for_malicious_tarball(path, filename)
        tar_file = tarfile.open(filename, 'r|gz')
        tar_file.extractall(path)
        image_file = tar_file.getnames()[0]
        tar_file.close()
        return os.path.join(path, image_file)
The software 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 software 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.