"In this article we will explain what TCP wrappers are and how to configure them to restrict access to network services running on a Linux server. Before we start, however, we must clarify that the use of TCP wrappers does not eliminate the need for a properly configured firewall."
"By Richard Adhikari
Aug 11, 2016 4:09 PM PT
A flaw in the RFC 5961 specification the Internet Engineering Task Force developed to protect TCP against blind in-window attacks could threaten Android smartphones, as well as every Linux computer on the planet. [*Correction - Aug. 12, 2016]"