Network Vulnerabilities The basic vulnerabilities associated with a network can be grouped into three broad categories: 1. Interception—The data that are transmitted over the network pass through some medium that consists of a carrier and other equipment, often in the physical control of other third parties. These data could be intercepted. Once intercepted, there is a risk of undesirable disclosure, i.e., someone
stealing data or modifying the intercepted data, resulting in loss of integrity and consequent other, more material losses. 2. Availability—As networks proliferate, more and more users are remote and access their applications over the network, crossing hundreds or thousands of miles. If network connectivity fails or becomes unavailable for any reason, there would be serious interruption to business and consequent damages. 3. Access/entry points—The network extends a computer system beyond the box into the world. The network provides the ability to extend the system to users across geographical boundaries, resulting in conveniences and efficiencies otherwise impossible. Conversely, the same network provides the feasibility for access to the system from anywhere. A single weak point in the network can make all the information assets in the network vulnerable to intruders. The network can provide many points of entry for intruders, interceptors and malicious code-like viruses, worms and Trojan horses. The ability of the network to enable access to a system from anywhere is the most serious of a network’s vulnerabilities. Given the fact that a major benefit of a network is its ability to provide access from elsewhere, the task at hand becomes discovering how best to devise controls around this access. Fortunately, the problem is not as formidable as it sounds. Access control solutions for the network exist in many forms and products that have been successfully deployed and tested.