Access Control Models Explained in Detail: PAM, MAC, DAC & RBAC

Access controls are responsible for determining who can access certain resources in an organization. Failure to restrict access can have great repercussions.

Access Control Models

Access controls are responsible for determining who can access certain resources in an organization. Failure to restrict access can have great repercussions. In fact, 99% of all misconfigurations in the public cloud go unreported. 

We’ll take a closer look at four of the most common access control models; PAM, MAC, DAC, and RBAC. We will also list the advantages and disadvantages of each access control model in the current evolving hybrid workplace.

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What is Privileged Access Management (PAM)?

Privileged Access Management (PAM) is a set of security solutions that manages user privileges by allowing or denying access to resources based on the level of privilege assigned to each user. 

74% of data breaches begin with privileged credential abuse. PAM ensures that credentials remain securely stored in a password vault and away from potential threat actors. 

It is important to note that PAM is not a single product but rather a framework of modules that can be used to provide different levels of access control.

Advantages of PAM

• Prevent privileged account attacks 
• Spot risky behavior with real-time monitoring 
• Manage access in a single location 
• Prevent the sharing of credentials with MFA authentication
• Stop permission creep when an employee changes job roles

Disadvantages of PAM

• Complex to set up for end-users  
• Costs can add up, especially if external training and resources are required
• The amount of time involved in managing PAM software

What is Role-Based Access Control (RBAC)?

Role-based access control (RBAC) is a security approach that restricts access to users based on roles within the organization. RBAC is perhaps the precursor to the Zero Trust security model, which assigns role-based permissions and limits employee access to corporate resources in order to prevent data breaches. 

It’s also important to point out that the cost of a breach without a Zero Trust approach in 2021 was $5.04 million but dropped down to $3.28 million when Zero Trust was implemented. Role-based access control is essential when securing remote access and preventing external attacks that can lead to major breaches.

Advantages of RBAC

• Increased flexibility by assigning roles to employees only when required
• Improves regulatory compliance as confidential data is managed more efficiently 
• Helps to easily integrate third-parties such as contractors and partners into your network by assigning them predefined roles
• Improves operational performance by eliminating the use of unnecessary applications that cause tool sprawl for IT admins
• Reduced administrative work 

Disadvantages of RBAC

• Role explosion which is when thousands of roles must be simultaneously managed across multiple applications
• Deployment can be quite complex, particularly in an enterprise environment 
• Access to specific actions in your system may be restricted but not to all data
• Administrators may forget to assign permissions

What is Mandatory Access Control (MAC)?

MAC is a system-controlled access to objects based on the level of clearance assigned to each user. MAC differs from other access control models in that it does not rely on user permissions but rather on security labels assigned to each resource and is controlled by a delegated administrator. 

Under MAC system controls, users cannot accidentally override a security policy as a system administrator sets all permissions. MAC systems are typically found in governments due to the high-level of security.

Advantages of MAC

• MAC provides tighter security as only an admin can alter controls, making it difficult for unauthorized users to access resources
• Subjects and objects have clearances and labels which are defined by secret or top secret in order to preserve highly confidential data

Disadvantages of MAC

• Clearing users is an expensive process
• Constant maintenance is required which can burden management 
• Complex to implement    
• The classification labeling can overwhelm users and limit productivity 
• It is not always compatible with certain applications or operating systems

What is Discretionary Access Control (DAC)?

Discretionary access control is a security system that allows users to access resources based on their permissions. DAC is among the most common types of access control and relies on a hierarchical structure in which administrators are granted greater privileges than regular users. 

Originally defined by the Trusted Computer System Evaluation Criteria (TCSEC) “as a means of restricting access to objects based on the identity of subjects and/or groups to which they belong.” DAC is based on access control lists (ACLs) to specific company resources. Discretionary access control is often discussed and paired with mandatory access control as both focus on securing the system from a higher level.

Advantages of DAC

• The authentication process is very strong  
• Lower administrative costs 
• Flexible

Disadvantages of DAC

• ACL maintenance can be a very exhausting process 
• Limited negative authorization power
• Difficulty audition due to extensive log entries

DAC vs MAC vs RBAC – And The Winner Is…

So, which access control model is the best? The answer is it depends on your organization’s needs. If you are looking for a reliable and secure option, RBAC is a good choice. If you are looking for a system that is easy to configure and manage, DAC is a good option. If you are looking for a system that is extremely secure, then MAC is ideal. 

Discretionary access control (DAC) offers the most flexibility as it allows anyone to assign controls and permissions to users without the approval of the IT department. Security policies should be enforced before granting any type of authorization to anyone. Make sure everyone is up to date on policies.

How to Choose the Right Access Control to Implement in Your Organization

Every business is different. An enterprise will require much more extensive and complex access controls to secure thousands of employees, entire departments, and third-parties from sophisticated cyber attacks. 

On the flip side, smaller businesses will have a lot more to worry about as they are far less equipped to handle a major breach. According to a recent study by Accenture, over 43% of SMEs are the target of a cyber attack. If the appropriate defensive measures aren’t set in place, they could very well be out of business. Another problem SMEs face is that many do not have dedicated IT staff and must outsource their security plan. 

So, how does an organization choose a particular access control model? Let’s flash forward to the present, where Zero Trust has eclipsed traditional controls as it goes beyond the restrictions of a physical VPN and offers a more granular level of security that can benefit any business, regardless of size or industry sector. Let’s take a closer look at how Zero Trust has redefined modern day security.