CISSP (ISC)2 Certified Information Systems Security Professional Official Study Guide. Gibson Darril

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СКАЧАТЬ of vulnerabilities and the avoidance, reduction, or mitigation of risk. Risk management, risk assessment, and addressing risk are all methods and techniques involved in performing process/policy review.

      Understand and Apply Risk Management Concepts

      Security is aimed at preventing loss or disclosure of data while sustaining authorized access. The possibility that something could happen to damage, destroy, or disclose data or other resources is known as risk. Understanding risk management concepts is not only important for the CISSP exam, it’s also essential to the establishment of a sufficient security stance, proper security governance, and legal proof of due care and due diligence.

      Managing risk is therefore an element of sustaining a secure environment. Risk management is a detailed process of identifying factors that could damage or disclose data, evaluating those factors in light of data value and countermeasure cost, and implementing cost-effective solutions for mitigating or reducing risk. The overall process of risk management is used to develop and implement information security strategies. The goal of these strategies is to reduce risk and to support the mission of the organization.

      The primary goal of risk management is to reduce risk to an acceptable level. What that level actually is depends on the organization, the value of its assets, the size of its budget, and many other factors. What is deemed acceptable risk to one organization may be an unreasonably high level of risk to another. It is impossible to design and deploy a totally risk-free environment; however, significant risk reduction is possible, often with little effort.

      Risks to an IT infrastructure are not all computer based. In fact, many risks come from noncomputer sources. It is important to consider all possible risks when performing risk evaluation for an organization. Failing to properly evaluate and respond to all forms of risk will leave a company vulnerable. Keep in mind that IT security, commonly referred to as logical or technical security, can provide protection only against logical or technical attacks. To protect IT against physical attacks, physical protections must be erected.

      The process by which the goals of risk management are achieved is known as risk analysis. It includes examining an environment for risks, evaluating each threat event as to its likelihood of occurring and the cost of the damage it would cause if it did occur, assessing the cost of various countermeasures for each risk, and creating a cost/benefit report for safeguards to present to upper management. In addition to these risk-focused activities, risk management requires evaluation, assessment, and the assignment of value for all assets within the organization. Without proper asset valuations, it is not possible to prioritize and compare risks with possible losses.

Risk Terminology

      Risk management employs a vast terminology that must be clearly understood, especially for the CISSP exam. This section defines and discusses all the important risk-related terminology:

      Asset An asset is anything within an environment that should be protected. It is anything used in a business process or task. It can be a computer file, a network service, a system resource, a process, a program, a product, an IT infrastructure, a database, a hardware device, furniture, product recipes/formulas, personnel, software, facilities, and so on. If an organization places any value on an item under its control and deems that item important enough to protect, it is labeled an asset for the purposes of risk management and analysis. The loss or disclosure of an asset could result in an overall security compromise, loss of productivity, reduction in profits, additional expenditures, discontinuation of the organization, and numerous intangible consequences.

      Asset Valuation Asset valuation is a dollar value assigned to an asset based on actual cost and nonmonetary expenses. These can include costs to develop, maintain, administer, advertise, support, repair, and replace an asset; they can also include more elusive values, such as public confidence, industry support, productivity enhancement, knowledge equity, and ownership benefits. Asset valuation is discussed in detail later in this chapter.

      Threats Any potential occurrence that may cause an undesirable or unwanted outcome for an organization or for a specific asset is a threat. Threats are any action or inaction that could cause damage, destruction, alteration, loss, or disclosure of assets or that could block access to or prevent maintenance of assets. Threats can be large or small and result in large or small consequences. They can be intentional or accidental. They can originate from people, organizations, hardware, networks, structures, or nature. Threat agents intentionally exploit vulnerabilities. Threat agents are usually people, but they could also be programs, hardware, or systems. Threat events are accidental and intentional exploitations of vulnerabilities. They can also be natural or manmade. Threat events include fire, earthquake, flood, system failure, human error (due to a lack of training or ignorance), and power outage.

      Vulnerability The weakness in an asset or the absence or the weakness of a safeguard or countermeasure is a vulnerability.

      In other words, a vulnerability is a flaw, loophole, oversight, error, limitation, frailty, or susceptibility in the IT infrastructure or any other aspect of an organization. If a vulnerability is exploited, loss or damage to assets can occur.

      Exposure Exposure is being susceptible to asset loss because of a threat; there is the possibility that a vulnerability can or will be exploited by a threat agent or event. Exposure doesn’t mean that a realized threat (an event that results in loss) is actually occurring (the exposure to a realized threat is called experienced exposure). It just means that if there is a vulnerability and a threat that can exploit it, there is the possibility that a threat event, or potential exposure, can occur.

      Risk Risk is the possibility or likelihood that a threat will exploit a vulnerability to cause harm to an asset. It is an assessment of probability, possibility, or chance. The more likely it is that a threat event will occur, the greater the risk. Every instance of exposure is a risk. When written as a formula, risk can be defined as follows:

      risk = threat * vulnerability

      Thus, reducing either the threat agent or the vulnerability directly results in a reduction in risk.

      When a risk is realized, a threat agent or a threat event has taken advantage of a vulnerability and caused harm to or disclosure of one or more assets. The whole purpose of security is to prevent risks from becoming realized by removing vulnerabilities and blocking threat agents and threat events from jeopardizing assets. As a risk management tool, security is the implementation of safeguards.

      Safeguards A safeguard, or countermeasure, is anything that removes or reduces a vulnerability or protects against one or more specific threats. A safeguard can be installing a software patch, making a configuration change, hiring security guards, altering the infrastructure, modifying processes, improving the security policy, training personnel more effectively, electrifying a perimeter fence, installing lights, and so on. It is any action or product that reduces risk through the elimination or lessening of a threat or a vulnerability anywhere within an organization. Safeguards are the only means by which risk is mitigated or removed. It is important to remember that a safeguard, security control, or countermeasure need not involve the purchase of a new product; reconfiguring existing elements and even removing elements from the infrastructure are also valid safeguards.

      Attack An attack is the exploitation of a vulnerability by a threat agent. In other words, an attack is any intentional attempt to exploit a vulnerability of an organization’s security infrastructure to cause damage, loss, or disclosure of assets. An attack can also be viewed as any violation or failure to adhere to an organization’s security policy.

      Breach A breach is the occurrence of a security mechanism being bypassed or thwarted by a threat agent. When a breach is combined with an attack, a penetration, or intrusion, can result. A penetration is the СКАЧАТЬ