This statement provides insight into how hackers may have been able to access his system. On October 24, NextCloud disclosed a remote code execution vulnerability (CVE-2019-11043) which has been exploited to compromise servers with the default Nextcloud NGINX configuration.
NGINX™ is a high performance edge web server with the lowest memory footprint and the key features to build modern and efficient web infrastructure.
Today NGINX is the 2nd most popular open source web server on the Internet.
via NGINX, Inc..