Information
Many Linux distributions provide value-added firewall solutions which provide easy, advanced management of network traffic into and out of the local system. When these solutions are available and appropriate for an environment they should be used.
In cases where a value-added firewall is not provided by a distribution, TCP Wrappers provides a simple access list and standardized logging method for services capable of supporting it. Services that are called from inetd and xinetd support the use of TCP wrappers. Any service that can support TCP wrappers will have the libwrap.so library attached to it.
Rationale:
TCP Wrappers provide a good simple access list mechanism to services that may not have that support built in. It is recommended that all services that can support TCP Wrappers, use it.
Solution
Run the following command to install TCP Wrappers:
# yum install tcp_wrappers
Impact:
Some Linux distributions have deprecated the use of TCP Wrappers in favor of value-added firewall solutions. In these cases the provided firewall solution should be used.
Notes:
To verify if a service supports TCP Wrappers, run the following command:
# ldd <path-to-daemon> | grep libwrap.so
If there is any output, then the service supports TCP Wrappers.