Nearly 4,500 servers with the Hadoop Distributed File System (HDFS) exposed more than 5,000 Terabytes (5.12 Petabytes) of data. This exposure is due to the same issue HDFS-based servers haven’t been properly configured. Most of the HDFS instances are hosted in the cloud with Amazon Web Services leading the charge with 1,059 instances and Alibaba with 507. While MongoDB has over 47,800 servers exposed on the Internet that exposes 25TB of data, Hadoops has just 4,487 servers in total.
Source: https://thehackernews.com/2017/06/secure-hadoop-cluster.html