If you’re planning to take the SY0-501 version of the Security+ exam, you should have a good understanding of identity and access management controls.
For example, can you answer this question?
Q. Your organization is implementing an SDN. Management wants to use an access control model that controls access based on attributes. Which of the following is the BEST solution?
A. DAC
B. MAC
C. Role-BAC
D. ABAC
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation are available at the end of this post.
Role-Based Access Control
Role-based access control (role-BAC) uses roles to manage rights and permissions for users. This is useful for users within a specific department who perform the same job functions. An administrator creates the roles and then assigns specific rights and permissions to the roles (instead of to the users). When an administrator adds a user to a role, the user has all the rights and permissions of that role.
Rule-Based Access Control
Rule-based access control (rule-BAC) uses rules. The most common example is with rules in routers or firewalls. However, more advanced implementations cause rules to trigger within applications, too.
Routers and firewalls use rules within access control lists (ACLs). These rules define the traffic that the devices allow into the network, such as allowing Hypertext Transfer Protocol (HTTP) traffic for web browsers. These rules are typically static. In other words, administrators create the rules and the rules stay the same unless an administrator changes them again.
However, some rules are dynamic. For example, intrusion prevention systems can detect attacks, and then modify rules to block traffic from an attacker. In this case, the attack triggers a change in the rules.
As another example, it’s possible to configure user applications with rules. For example, imagine you want to give Homer additional permissions to a database if Marge is absent. You can configure a database rule to trigger a change to these permissions when the system recognizes that Marge is absent.
The 601 Version of the Study Guide
The CompTIA Security+: Get Certified Get Ahead: SY0-601 Study GuideEach of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.
Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
Discretionary Access Control
In the discretionary access control (DAC) model, every object (such as files and folders) has an owner, and the owner establishes access for the objects. Many operating systems, such as Windows and most Unix-based systems, use the DAC model.
A common example of the DAC model is the New Technology File System (NTFS) used in Windows. NTFS provides security by allowing users and administrators to restrict access to files and folders with permissions.
Attribute-Based Access Control
An attribute-based access control (ABAC) evaluates attributes and grants access based on the value of these attributes. Attributes can be almost any characteristic of a user, the environment, or the resource. ABAC uses policies to evaluate attributes and grant access when the system detects a match in the policy.
As a simple example, Homer is a Nuclear Safety Inspector at the Springfield Nuclear Power Plant. His user account may be defined with the following attributes: employee, inspector, and nuclear aware. A file server at the plant includes a share called Inspector and it holds documents commonly used by nuclear safety inspectors. An ABAC policy for the share might grant access to the share for any subjects that have the attributes of employee, inspector, and nuclear aware. Many software defined networks (SDNs) use ABAC models. Instead of rules on physical routers, policies in the ABAC system control the traffic. These policies typically use plain language statements. For example, an ABAC policy rule for a company that employs researchers might be “Allow logged-on researchers to access research sites via the main network.” Policy statements typically include four elements:
• Subject. This is typically a user. You can use any user property as an attribute such as employment status, group memberships, job roles, logged-on status, and more. In the example, the subject is identified as being logged on and a member of a researchers group.
• Object. This is the resource (such as a file, database, or application) that the user is trying to access. In the example, the object is research sites. The research sites object would include Internet access via a proxy server along with a specific list of URLs of research sites.
• Action. The action is what the user is attempting to do, such as reading or modifying a file, accessing specific web sites, and accessing web site applications. The example allows access to specific web sites.
• Environment. The environment includes everything outside of the subject and object attributes. This is often referred to as the context of the access request. It can include the time, location, protocols, encryption, devices, and communication method. In the example, it specifies the main network as an environmental attribute.
An ABAC system has a lot of flexibility and can enforce both a DAC and a MAC model. There are also many similarities between the ABAC model and the DAC and MAC models. In the DAC model, owners have control over the access and in an ABAC model, owners can create policies to grant access.
The MAC model uses labels assigned to both subjects and objects and grants access when the labels match. The ABAC model uses attributes that identify both subjects and objects, and grants access when a policy identifies a match.
Q. Your organization is implementing an SDN. Management wants to use an access control model that controls access based on attributes. Which of the following is the BEST solution?
A. DAC
B. MAC
C. Role-BAC
D. ABAC
Answer is D. A software defined network (SDN) typically uses an attribute-based access control (ABAC) model, which is based on attributes that identify subjects and objects within a policy.
A discretionary access control (DAC) model has an owner, and the owner establishes access for the objects.
A mandatory access control (MAC) model uses labels assigned to subjects and objects.
A role-based access control (role-BAC) model uses roles or groups to assign rights and permissions.
See Chapter 2 of the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide for more information on access control models.
