Chapter 2. Understanding VulnerabilitiesThe Need for Security

On completing this chapter, you will be able to

• Explain the weaknesses of the TCP/IP protocol suite

• Describe various types of attacks that exploit weaknesses in the TCP/IP protocol suite

• Explain how attackers cause buffers to overflow

• Describe how attackers use spoofing techniques

• State how attackers use social engineering techniques to capture passwords

On completing this chapter, you will better understand what makes computer systems inherently weak. The chapter covers various vulnerabilities and attack techniques. You will get a clear indication of the need for security, especially the need for assigning the proper responsibilities in the organization.

In general, vulnerabilities can be best described as weaknesses that can be exploited to someone's benefit. In particular, network security vulnerabilities are weaknesses in network security products, network security implementations, or even in network design that can be exploited to violate a corporate network security policy.

The motivation for an individual or organization to attack or harm other persons or property can have multiple sources. These sources can be political, religious, or personal. This book focuses solely on network attacks. Network attacks are attempts to damage, sabotage, or steal the property of an organization (for instance, an organization's website) in order to gain information and competitive advantage.

Besides knowing or at least trying to understand the motivation for the attacks, it is important to comprehend the real threats that exist in your environment. What types of threats are there? Are there individuals or groups of individuals trying to harm other individuals or groups, steal proprietary information, or just do damage?

Harm to a network can damage individuals. For example, a reputation can be abused if an attacker steals someone's credit card details or identity on the Internet. In a similar way, the reputation of an organization can be damaged. Attackers steal proprietary information by breaking into an organization's websites to gain a competitive edge by learning product features or sabotaging test results.

In order to protect your organization against possible attacks, you must take appropriate security measures. Once you understand the likelihood of an attack and are aware of existing threats, it is important to define proper security measures. The following sections elaborate on existing network security vulnerabilities and threats.