I’ve recently fielded a few questions about security controls related to the Security+ exam. They are important topics for the exam and I answered the queries, but it gave me the idea of this blog post too.
As a brief explanation, security controls attempt to prevent or limit the impact of a security incident. For example, antivirus software is a technical security control that attempts to prevent malware infections.
Security Controls – Implementation Methods
One method of classifying security controls is based on how they are implemented. The three common implementation classifications are technical, management, and operational:
- Technical controls use technology.
- Management controls use administrative or management methods.
- Operational controls are implemented by people in day-to-day operations.
Security Controls – Goals
Another way of classifying security controls is based on their goals in relationship to security incidents. Some common classifications are preventive, detective, corrective, deterrent, and compensating.
- Preventive controls attempt to prevent an incident from occurring.
- Detective controls attempt to detect incidents after they have occurred.
- Corrective controls attempt to reverse the impact of an incident.
- Deterrent controls attempt to discourage individuals from causing an incident.
- Compensating controls are alternative controls used when a primary control is not feasible.
Security Controls – Questions
Can you differentiate between the different controls? Try these questions to test your knowledge.
Q1. You need to reduce the attack surface of a web server. Which of the following is a preventive control that will assist with this goal?
A. Identifying the initial baseline configuration
B. Disabling unnecessary services
C. Using hardware locks
D. Monitoring logs for trends
Answer and explanation at end of post.
Q2. A security expert is identifying and implementing several different physical deterrent controls to protect an organization’s server room. Which of the following choices would BEST meet this objective?
A. Using hardware locks
B. Utilizing data encryption
C. Performing a vulnerability assessment
D. Training users
Answer and explanation at end of post.
If you want to read more about security controls, check out this series of posts:
Security Control Goals continued
Security Control Implementation Methods
Security Controls – Question Answers
Q1. You need to reduce the attack surface of a web server. Which of the following is a preventive control that will assist with this goal?
A. Identifying the initial baseline configuration
B. Disabling unnecessary services
C. Using hardware locks
D. Monitoring logs for trends
Q1 Answer B is correct. Disabling unnecessary services is one of several steps you can take to harden a server and it is a preventive control.
A is incorrect. Identifying the initial baseline configuration is useful to determine the security posture of the system, but by itself it doesn’t prevent attacks.
C is incorrect. Hardware locks are useful to protect a server room where a web server operates, but it doesn’t reduce the attack surface.
D is incorrect. Monitoring logs and trend analysis are detective controls, not preventive controls.
Q2. A security expert is identifying and implementing several different physical deterrent controls to protect an organization’s server room. Which of the following choices would BEST meet this objective?
A. Using hardware locks
B. Utilizing data encryption
C. Performing a vulnerability assessment
D. Training users
Q2 Answer A is correct. A hardware lock is a physical security control. It’s also a deterrent control because it would deter someone from entering.
B is incorrect. Data encryption is a technical control designed to protect data and is not a physical security control.
C is incorrect. A vulnerability assessment is a management control designed to discover vulnerabilities, but it is not a physical control.
D is incorrect. Training users is an effective preventive control, but it is not a physical control.
