What Is the Principle of Least Privilege?

The principle of least privilege, or PoLP, is an important concept in cybersecurity and information technology. It suggests that any system, user, or process should have access to only the absolute minimum privileges necessary to perform its function or task. This principle is integral to limiting the potential damage that could occur if a system or user were compromised.

The principle of least privilege is not a new concept. It has been at the core of computer security for several decades. However, its implementation and understanding have grown in importance with the increased complexity and interconnectedness of digital systems. The principle is based on the assumption that every software process, system, or user can potentially be exploited, and therefore, the fewer privileges a process or user possesses, the fewer opportunities there are for exploitation.

Implementing the principle of least privilege requires a thorough understanding of the system or process and its requirements. It also requires a commitment to ongoing management and review, as the needs of a system or user may change over time.

In this article:

What are Privileged Users or Entities? 

Privileged users or entities are those that have been granted more access rights or permissions than regular users. These could be system administrators, network engineers, or even specific applications or processes that require elevated privileges to function correctly.

Privileged users are a necessary part of any system. They are the ones who keep the systems running, ensure the security measures are in place, and fix any issues that may arise. However, they also represent a potential security risk. If a privileged user account is compromised, the attacker could potentially gain access to sensitive data or critical system functions.

Privileged entities can include applications or processes that require more access to function correctly. Examples include system processes, database applications, or network services. Like privileged users, privileged entities also represent a potential security risk if they are compromised or misused.

Therefore, managing and restricting privileged users and entities is a critical aspect of implementing the principle of least privilege. This involves carefully defining the necessary access for each user or entity, regularly auditing and reviewing these privileges, and ensuring that any unnecessary privileges are revoked promptly.

What Is Privilege Creep? 

Privilege creep is a common issue in IT systems. It refers to the gradual accumulation of access rights by users or entities over time. This could happen for various reasons, such as changes in roles or responsibilities, temporary assignments, or oversight. Regardless of the cause, privilege creep represents a significant security risk and is contrary to the principle of least privilege.

Once a user or entity has been granted a specific privilege, it is easy to forget to revoke that privilege when it is no longer needed. Over time, these forgotten privileges can accumulate, leading to users or entities with far more access rights than they require to perform their tasks. This provides more opportunities for potential exploitation and increases the potential damage if a system or user is compromised.

Preventing privilege creep requires a proactive and ongoing approach to privilege management. This includes regular audits of user and entity privileges, prompt revocation of unnecessary privileges, and the use of automated tools to help manage and monitor access rights. It also requires a company culture that values security and understands the importance of the principle of least privilege.

What Are the Benefits of the Principle of Least Privilege? 

Minimizes the Attack Surface

By limiting the access rights of users, the potential points of entry that attackers can exploit are significantly reduced. Applying the principle of least privilege means that even if an attacker manages to compromise a user account, their ability to cause damage or access sensitive data is limited.

Reduces Malware Propagation

If a system or device is infected by malware, and its user account has limited privileges, the malware’s ability to spread to other systems or perform damaging activities is likewise restricted.

By ensuring that all users and applications operate under the least possible privileges, the potential for malware to spread or cause significant damage is greatly reduced. This is particularly important in today’s threat landscape where ransomware and other forms of malware are increasingly sophisticated and damaging.

Improves Operational Performance and Stability

By restricting user privileges to only what is necessary, unnecessary system interactions can be reduced, which can lead to improved system performance.

Additionally, the principle of least privilege can lead to improved system stability. Overly permissive access rights can lead to unintentional system changes, which can result in system instability. By enforcing least privilege, these potential risks can be mitigated, leading to more stable and reliable systems.

Safeguards Against Human Error

The principle of least privilege also acts as a safeguard against human error. Even the most well-meaning employees can make mistakes, and these mistakes can have serious consequences if the user has broad system access. By limiting access rights, the potential impact of human error is minimized.

Examples of the Principle of Least Privilege 

The principle of least privilege can be applied in many different contexts, from user accounts to system processes. Here are a few practical examples of how this principle can be implemented.

Network User Accounts with Least Privilege

A simple example of the principle of least privilege is the creation of user accounts with only the necessary access rights for their roles. For instance, a salesperson requires access to a customer relationship management (CRM) system and network resources within their department. By contrast, a network administrator will have broad access to the entire network. By assigning appropriate privileges based on job requirements, the potential for accidental or intentional misuse of privileges is greatly reduced.

Database Users with Least Privilege

It is common to create database “superusers”, with broad access to the entire database, but this practice goes against the principle of least privilege. When creating database users according to the least privilege principle, each user account is given only the necessary permissions to perform their roles, such as reading from or writing to specific database tables. Databases provide granular permissions that make it possible to restrict the scope of data and specific operations each account is allowed to perform.

Using Just in Time Least Privilege

Another application of the principle of least privilege is the use of just in time (JIT) privilege, where users are granted privileges only when they need them and for a limited time. A common example is IT staff who need to perform emergency maintenance on critical systems. A JIT privilege system can provide access to these staff for a limited time (for example, 24 hours), and automatically revoke privileges when the time window has elapsed.

Privileged Users and the Cloud 

When it comes to cloud computing, the risk associated with privileged user accounts is amplified. In a cloud environment, these accounts often have the ability to access vast amounts of sensitive data. Additionally, they can make changes that impact the entire cloud environment, including turning off security controls, modifying templates or images used to create multiple cloud resources, deleting data, and even shutting down entire systems.

The principle of least privilege is particularly crucial in a cloud environment. By limiting the permissions of each user to only what they need to complete their job, you can significantly reduce the risk of a breach. Even if a privileged account is compromised, the damage they can do is limited.

How to Implement the Least Privilege in Your Organization 

The following steps outline a methodical approach to achieving the principle of least privilege.

Audit the Full Environment to Locate Privileged Accounts

An audit of privileged accounts should include not only user accounts but also system and service accounts that may have elevated permissions. Once these accounts have been identified, it’s important to document who has access to these accounts, what permissions they have, and why they need these permissions. This information will be crucial in the next steps of the process.

Eliminate Unnecessary Local Administrator Privileges

In many organizations, local administrator privileges are handed out liberally. Users are often given these privileges to install software, make system changes, or for convenience. However, these privileges also come with significant risk.

Once you’ve identified who has local administrator privileges, it’s time to start removing these rights where they are not necessary. This process should be done carefully and methodically to avoid disruption to users and systems.

Separate Administrator Accounts from Standard Accounts

One common mistake many organizations make is not separating administrator accounts from standard user accounts. This means that administrators use the same account for daily tasks as they do for tasks requiring elevated permissions.

By separating these accounts, you can ensure that administrator privileges are only used when necessary. This not only reduces the risk associated with these accounts but also makes it easier to monitor and audit their use.

Immediately Rotate Administrator Passwords After Each Use

Another important step in implementing the principle of least privilege is to rotate administrator passwords immediately after each use. This helps to prevent unauthorized access if a password is accidentally shared or stolen.

There are many tools available that can automate this process, making it easier to manage. These tools can also enforce complex password requirements, further enhancing security.

Continuously Monitor All Activity Related to Administrator Accounts

Even with all these precautions, it’s still important to continuously monitor all activity related to administrator accounts. This includes both logins and changes made using these accounts.

By monitoring these accounts, you can quickly identify any suspicious activity and respond before it becomes a significant issue. This is a crucial part of an effective incident response plan.

Consistently Review All Cloud IAM Permissions and Entitlements

The final step in implementing the principle of least privilege is to consistently review all cloud Identity and Access Management (IAM) permissions and entitlements. These permissions and entitlements determine who can access your cloud resources and what they can do with them.

By regularly reviewing these permissions, you can ensure that they are in line with the principle of least privilege. This not only helps to secure your cloud environment but also helps to maintain compliance with various standards and regulations.

How to Protect Against Lateral Movement with Aqua

To prevent lateral movement in your cloud native environment, you need to follow security best practices and minimize your attack surface. One of the approaches is to implement identity-based segmentation of your network. This will allow you to discover, visualize, and define network connections in cloud native environments and detect any malicious network activity across VMs, containers, Kubernetes clusters, and pods. 

With the unified Aqua Cloud Native Security Platform, you can:

  • Detect and prevent unauthorized network connections such as open ports (on the same or across hosts and pods) based on automated policies.
  • Define zero-trust network connections based on service-oriented firewall rules, regardless of where the workload runs.
  • Automatically alert on or block unauthorized communication flows with no container downtime.
The Cloud Native Experts
"The Cloud Native Experts" at Aqua Security specialize in cloud technology and cybersecurity. They focus on advancing cloud-native applications, offering insights into containers, Kubernetes, and cloud infrastructure. Their work revolves around enhancing security in cloud environments and developing solutions to new challenges.