Workers for local Dask clusters mistakenly listened on public interfaces
Versions of distributed earlier than 2021.10.0 had a potential security vulnerability relating to single-machine Dask clusters. Clusters started with dask.distributed.LocalCluster or dask.distributed.Client() (which defaults to using LocalCluster) would mistakenly configure their respective Dask workers to listen on external interfaces (typically with a randomly selected high port) rather than only on localhost. A Dask cluster created using this method AND running on a machine that has these ports exposed could be …