Architecture with Multiple Layers of Firewalls

There is no limitation on where a firewall can be placed in a network. While firewalls should be at the edge of a logical network boundary, creating an “inside” and “outside” on either side of the firewall, a network administrator may wish to have additional boundaries within the network and deploy additional firewalls to establish such boundaries.

The use of multiple layers of firewalls is quite common to provide defense-in-depth. For [..]

Extranet VPN

Almost every company has a select group of suppliers, vendors and other business partners they do business with. Business interactions between these organisations include communication, collaboration and, in many cases, commercial transactions.

In today’s rapidly changing and highly competitive global economy, speed and cost can determine a company’s success or failure. As the traditional business exchange methods often prove to be slow, paper-based, timeintensive, and expensive, companies are looking to improve [..]

Understanding Hidden Threats: Corrupted Software Files

Malicious code is not always hidden in web page scripts or unusual file formats. Attackers may corrupt types of files that you would recognize and typically consider safe, so you should take precautions when opening files from other people.

What types of files can attackers corrupt?

An attacker may be able to insert malicious code into any file, including common file types that you would normally consider safe. These files may include [..]

Microsoft SQL Server Vulnerability

Microsoft has released Security Advisory 961040 to address reports of attacks against a new vulnerability in Microsoft SQL Server 2000, Microsoft SQL Server 2005, Microsoft SQL Server 2005 Express Edition, Microsoft SQL Server 2000 Desktop Engine, Microsoft SQL Server 2000 Desktop Engine, and Windows Internal Database. The vulnerability occurs in the extended stored procedure “sp_replwriteovarbin.”[..]