Yes or no to firewall request to act as server?

By Fred Langa It’s not always easy to tell whether a program really needs the rights and privileges of a server. When your firewall alerts you that an application wants to act as a server, you have two simple ways to determine the correct response.

Find out why a program wants server status

Maurice Carson ran into one of those all-too-common, half-explained firewall queries:

• “What about programs wanting to ‘act as a server’? I have ZoneAlarm as a firewall, and many programs want to act as a server. Why?”
  

First, let’s define the jargon. A “server” is a program that responds to a request from another program to open a connection, send or receive a file or data, launch a program, or perform some other task. A “client” is a program that makes such a request.

Technically, client and server programs can reside on the same machine. Security risks come into play when the client and server are on separate networked machines. Some programs are both clients and servers, while others — known as “standalone applications” — are neither.

ZoneAlarm and other security tools are especially suspicious of any program that wants to act as a server, because letting other PCs request data or services from your system is obviously risky. The firewall has no way of knowing whether the request to act as a server is legitimate, so it punts the decision to a human — you.

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