local char *justname(char *path)
{
    char *p;

    p = strrchr(path, '/');
    return p == NULL ? path : p + 1;
}

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.