What Is the Principle of Least Privilege & Why Does It Matter?

The principle of least privilege can improve the security of your system. Learn what the principle of least privilege is, how it works, and best practices. 

What is the Principle of Least Privilege?

The Principle of Least Privilege states that users should only be given the minimum privileges necessary to complete their tasks. Benefits of the principle of least privilege include:

• Better security

• Reduced liability

• Increased audit readiness

• Prevention against common attacks

The principle of least privilege (PoLP) has been aptly called the principle of minimal privilege or least authority. PoLP emanates from the concern that once you give users access to parts of a system, there’s going to be the possibility of abuse or misuse. Hence, the need to curtail such risks.

This information security philosophy has grown more important and common with the increasingly complex and interconnected nature of modern information systems. We have entered an age of rapid digital transformation fostered by the cloud and driven by the massive number of endpoints accessing corporate networks, whether through user devices, APIs, or third-party applications. This expansion requires more stringent applications of who can access what information and why.

This digital transformation and rapid technological developments have likewise broadened the attack surface exposed to hackers, leading to the proliferation of multi-layer attack paths. The principle of least privileges is therefore a mitigation strategy that attempts to minimize user and application privileges. It ultimately aims to prevent any attacker who gains a foothold in the system from escalating their privileges through lateral movements or multi-step attack paths, and aims to ensure that only those who need more privileged access to sensitive information, have it

However, as we have previously highlighted, the least privilege principle isn’t a silver bullet for solving cloud security. As a result, the cloud security gaps surrounding least privilege need to be shored up with heightened focus to ensure the right users have the correct access.

How Does the Principle of Least Privilege Work?

One of the best analogies for highlighting least privileged access is to compare and contrast it with the difference between providing a key that works on every door and one that only opens specific rooms. No sensible organization provides anyone a key to a door they don’t need access to. In the same vein, PoLP ensures users only have the single key to the single door required for them to gain work-related access, and no permissions beyond that.

More importantly, least privilege is one of the main pillars of zero-trust security.

Zero-trust and PoLP have gained increased adoption with the large-scale migration to the cloud by organizations. This mainly occurred because the older “castle- and-moat” strategies of traditional perimeter defenses no longer suffice for the scale of vulnerabilities faced today. 

Here are some guidelines for implementing the principle of least privilege:

1. Implementing Data Discovery and Classification 

One of the vital steps in the PoLP implementation process should involve the classification of sensitive data. Only after identifying and enumerating confidential and sensitive data in your environment can the necessary process of safeguarding them by controlling and apportioning their rightful access begin.

The good news is that the major cloud service providers offer data classification features out-of-the-box, even going as far as intuitively classifying data as soon as it is created. However, you shouldn’t outsource this process entirely but perform routine audits to ensure company secrets, proprietary information, and personally identifiable information (PII) are adequately classified. 

2. Implement Role-Based Access Control (RBAC)

The principle of least privilege works in tandem with role-based access control (RBAC). RBAC mirrors the least privilege principle as it is designed to limit an employee or vendor’s access to certain programs or data on a corporate network based on their roles within the organization. 

A prime example of the least privilege in operation is computer operating systems. They allow different user and group profiles to be created on the same system and network. However, their activities are delineated by their different roles within the system, each accompanied by respective privileges tailored to each user profile. 

This concept is also extended and practiced by digital rights management and information rights management systems. In addition to providing least privilege through robust identity access management (IAM), they also typically provide only a time-limited window to perform a minimum set of actions on files like copying, printing, editing, or viewing. 

The essence of these measures is to mitigate identity-related risks. Moreover, this is facilitated by conceiving a user role, especially within the context of an organization, as a collection of access privileges linked to a job title or job description.

3. Identify and Remove Inactive User Accounts

Practicing good data sanitation is essential in cybersecurity. One of its hallmarks is removing duplicate and redundant data, especially for privileged accounts.

Leaving redundant and duplicate data to hang around can result in them becoming possible access points for security compromise. The same goes for inactive accounts. These accounts are typically less monitored so hackers can target them easily without detection, then surreptitiously elevate the privileges of the compromised accounts. 

4. Implement Real-Time Monitoring For Privileged Accounts

A corollary to the preceding point is the need to monitor privileged accounts in real-time. This can be achieved by embracing CSPM tools that provide visibility and auditing features, often equipped with machine learning capabilities to detect anomalous user behavior. 

Tools that monitor high-profile accounts typically first establish a baseline of normal user behavior and subsequently flag deviations from those activities. 

Least Privilege Best Practices

Here are some best practices and rules of thumb you should observe when implementing PoLP:

• Regularly conduct privilege audits. All existing accounts and processes should be regularly examined to ensure they maintain only the minimum permissions required.
• All accounts should start with least privilege. PoLP should always be the default access mode for all roles in the system or organization.
• Use Just In Time (JIT) access. Only expand or elevate access on a case-specific and one-time basis, only limited to moments when they are needed, and with strict oversight.
• Identify, separate, and enforce system separation. Ensure high-level functions are differentiated from lower-level ones; ditto for the critical and the non-critical actions. This makes it much clearer who is accessing what information, and with visibility into how the data is protected.
• Monitor all accounts. Accounts should be traceable, with their network activity easily monitored and audited, preferably with a user access management console. 

The Benefits of the Principle of Least Privilege

The principle of least privilege is a security strategy that provides many benefits. While it is based on the idea of granting only the necessary permissions needed for the execution of a task or activity, it can be extended to any technological system where resources are shared amongst a broad swath of users with different responsibilities. 

The Principle of Least Privilege Improves Overall IT Security

Providing users, devices, and applications with access to only the information they require is a hallmark of good cybersecurity.  It also helps to adequately address issues of access control, permissions, and privileges at the granular level of user or resource identity.

The first way PoLP enhances security is by reducing an organization’s attack surface and risk exposure. 

One of the compelling reasons companies should prioritize least privilege is because most advanced threats rely on the exploitation of privileged credentials. When paired with zero-risk security, least privilege access acts as a powerful safeguard against the escalation of privilege attacks. This is primarily because it prevents hackers from implementing incremental, multi-step attacks. 

Furthermore, at the core of least privilege is stringent access control, which works by robustly limiting the range of operations a user is allowed to execute. The corollary is that it also limits the damage and risk exposure a user can inflict on the organization — this is true whether it occurs through hacker-compromised accounts, negligence, or even malicious insider threats. 

Secondly, the principle of least privilege limits the propagation of malware.

Enforcing PoLP at endpoints equally prevents hackers from using, say, SQL injection attacks (adding malicious code to database queries) to exploit a security vulnerability and subsequently move laterally to propagate and spread malware inside the network. Hence, malware is more easily contained in the section where it entered the system, further isolating the amount of damage it can wreck.

The Principle of Least Privilege Improves a System’s Overall Stability

The least privilege principle is also an important design principle. In addition to security, it provides an application system with much-needed stability. 

PoLP is implemented by applying computer code to create an abstraction layer that gives software artifacts access to only the data and information they need for legitimate activities. The code is consequently written to limit the scope of changes a single agent can unleash on the system. 

This self-imposed isolation and clear delineation of boundaries creates atomized actions. As a result, it is easy to perform unit and regression tests to evaluate possible actions and interactions within the application, and their side-effects. In doing so, it improves the security and stability of the underlying software architecture. 

So, while PoLP enhances the security of data, it also increases the fault tolerance of an application’s functionality, ultimately making the system architecture more robust.

Least Privileged Access Helps Streamline Compliance and Audits

Most industry regulations typically require the implementation of PoLP. The process of implementing PoLP such as data, resource, and user identity classification compels organizations to create audit trails and adhere to stringent compliance requirements. 

Least Privilege Principle Reduces Exposure to Liabilities

In addition to containing and minimizing the damage unleashed by an attack, least privileged access also reduces the liability exposure of a targeted organization.

When users or digital agents are allowed to go beyond their rights or mandate, it creates an environment rife with potential unintentional or intentional abuse. Without least privilege, users will carry out actions they should normally not be authorized to execute, like viewing, accessing, and/or modifying confidential business or personal information they shouldn’t be privy to.  

This can result in costly legal, financial, and reputational implications for the organization.

Least Privilege Principle Improves Identity Governance

In conjunction with RBAC, least privilege helps an organization establish consistent access policies to keep the business secure. For instance, the use of roles simplifies identity governance. Therefore, organizations can conscientiously define roles, appropriately assign those roles, and review access to them.  

In addition to allowing access privileges to be defined ahead of time, it boosts efficiency for the company, especially as the business continues to grow and evolve.

Least Privilege in a Cloud Environment: User Discretion Advised

However, as much as the principle of least privileges is viewed as a security best practice, it isn’t a failsafe approach, especially in a cloud architectural model.  We have highlighted how the least privilege concept is a carryover from the on-premise security paradigm. Therefore, some of its built-in advantages don’t translate well with cloud-native deployments.

As a result, cloud security teams should be careful when adopting the concept of least privilege.

Here’s a recap of some issues we discovered when organizations wholeheartedly import PoLP into the cloud without qualification:

• One or two permissions in cloud environments can provide sufficient conditions to achieve superuser privileges.
• The illusion that you can fully control a dynamic cloud environment with user access roles and managed policies doesn’t hold up to reality.

Detect and Remediate Least Privilege Problems with Lightspin

While PoLP is ideal as a best practice to shoot for, businesses need to realize that least privilege worked most effectively before the cloud era.

At Lightspin, we approach the problem by offering our dynamic Guardrails solutions that allows security teams to create their own managed policy unique to their specific environment. By remediating specific attack paths, Guardrails renders the issue of least privilege moot. In addition to allowing teams to apply access controls, Guardrails is also non-intrusive so your team can work unhindered. 

Lightspin’s enhanced contextual security for cloud environments provides automatic adjustments for security permissions and accurate prioritization of threats. This proves to be the best way to restrict access in a smart way. 

To learn more, try out our free demo today.

*** This is a Security Bloggers Network syndicated blog from Lightspin Blog authored by Lightspin. Read the original post at: https://blog.lightspin.io/devsecops/principle-of-least-privilege