I just had to deal with an insecure default in our Hadoop cluster. Hadoop, by default, enables WebHDFS, which provides read+write access to HDFS over HTTP. The

I just had to deal with an insecure default in our Hadoop cluster. Hadoop, by default, enables WebHDFS, which provides read+write access to HDFS over HTTP. The service runs on name node using the same port which displays the Hadoop Jobs Web UI. Now, it is very easy to not know anything about WebHDFS and every day authenticate/login to server, submit jobs, and track the status on WebUI (which is public). But then anyone can send a POST request pretending to be any user and Hadoop will happily execute the command (including deleting all files). Maybe Hadoop developers believe that all Hadoop installations are behind a firewall (ours was, but an exception was made for Jobs Web UI as it seemed to be a read-only status page for running jobs) and/or have Kerberos integrated with Hadoop for authentication. But that being said, enabling HDFS access over HTTP by default seems to a debatable choice. Also, if you have a small Hadoop cluster running, do set "dfs.webhdfs.enabled" property to False in hdfs-site.xml.