Availability controls ensure that information and systems are available for the use of authorized individuals when needed. They protect against denial-of-service attacks that hackers might use to prevent legitimate use of information systems. Availability controls include fault tolerance, redundant components, and clustered servers.
- [Instructor] As a security professional, you must also understand how to apply security controls that protect the availability of information and systems. As the third leg of the CIA triad, availability controls ensure that information and systems remain available to all the authorized users when needed. Availability controls protect against disruptions to normal system operation or data availability. Potential availability failures may result from a variety of causes such as malicious attackers, like someone conducting a denial of service attack to bring down a website.
Or component failures such as the failure of a hard drive or power supply. They can also come from application failures such as errors in code that cause an application crash. Or utility failures such as a power outage that disrupts systems or a network disruption that prevents internet access. There are many controls in place that can protect the availability of systems and information. One example of an availability control is the use of redundant components such as including two power supplies in a system or having extra hard drives that use RAID technology.
Another example is the use of high availability systems that have multiple servers dedicated to the same purpose so that if one server fails, the others may continue carrying the operational load. And the more general category of fault tolerance ensures that IT services remain functioning even when small failures occur. There is one additional availability control that you should be familiar with for the CISSP exam. Keeping operating systems and applications patched to current levels ensures that any flaws identified by the manufacturer are corrected promptly.
This not only protects your system from vulnerabilities that might allow an attacker to gain access, but also corrects issues that may cause a system to crash, disrupting availability.
Members who complete this course will be prepared to answer questions on the Security and Risk Management domain of the CISSP exam, and establish a critical foundation for the rest of their careers.
Find the companion study books at the Sybex test prep site and review the complete CISSP Body of Knowledge at https://www.isc2.org/cissp-domains/default.aspx.
- Aligning security with the business
- Using control frameworks
- Understanding compliance ethics
- Implementing effective security policies
- Ensuring the security of employees
- Managing risk
- Identifying threats
- Managing vendors
- Building security awareness and conducting security training