What is the principle of least privilege?
The principle of least privilege (PoLP) is a network and cybersecurity principle that advocates for allocating only the bare-minimum privileges required by each user, software service, and connected device in order to prevent security breaches or minimize their potential impact.
Excessive privileges—unguarded access to sensitive data—can increase the risk of data breaches. For instance, if threat actors deploy a phishing link to access an employee account responsible for database updates, but a PoLP strategy is already in place, the potential damage from the hack will be isolated to the employee’s limited reach. However, if the employee has unlimited/root access (e.g., the ability to export or delete sensitive data from the database), then the attack can be disastrous, damaging customer trust and resulting in hefty fines.
PoLP is often used interchangeably with “need to know.” At the heart of PoLP are the terms privilege and privileged accounts:
A privilege is the access level granted to a user or account, such as the ability to access or modify kernel functions or form data through a MySQL account.
Privileged accounts, on the other hand, are administrative accounts with elevated access to critical organizational resources and operations. In contrast to the limited reach of regular and least privileged user accounts (LUA), privileged accounts can perform functions such as (re)configuring settings and installing software, elevating the risk they pose if compromised. Privileged access management (PAM), a mechanism within PoLP, is deployed to safeguard privileged accounts to lessen these risks.
Why PoLP matters
Imagine a family with a large house and a couple dogs. The family hires a housekeeper, a babysitter, and a pet sitter to help them with the daily tasks of running the household while they are away.
The principle of least privilege would state that each employee should only be given the access and permissions necessary to perform their job duties. For example, the housekeeper should only have access to the rooms in the house that they need to clean. The babysitter should only have access to the areas of the house where the children play, eat, and sleep. And the dog sitter should only have access to the areas of the house necessary to feed the dogs and take them out for walks.
Reducing access of each employee not only helps to reduce the risk of theft or damage, but also reduces the risk of a mistake (lost keys, leaving a door unlocked) that could compromise the family's security. In the event that theft or a mistake does occur, least privilege makes it much easier to identify the cause because you know who had access to what, and when they had access.
PoLP is also important because it involves regular access reviews and audits to prevent privilege creep—a situation where users gradually accumulate more privileges than they actually need due to job changes and inadequate PAM. Privilege creep increases the risk of data breaches, misuse of privileges, and noncompliance with regulations (including GDPR, CCPA, HIPAA, and PCI DSS) because privileged users can maliciously or inadvertently exploit their access creep. To combat these vulnerabilities, PoLP solutions regularly evaluate personnel and software privileges to ensure that they align with current needs and roles.
Real-life examples
Here are two real-life examples where PoLP could have saved the day:
An engineer at General Electric stole more than 8,000 sensitive files containing trade secrets in order to start a rival firm. This breach occurred because the employee operated a privileged account that allowed him root access to the organization’s resources, a situation that PoLP could have prevented. Discovered in 2022, the breach had a dwell time of more than eight years and could have been remediated much earlier with the implementation of PoLP’s regular access reviews.
Across two weeks in March 2022, a malicious actor hacked Shields Health Care Group’s network server and exfiltrated patients’ PII and PHI, including full names, addresses, credit card numbers, diagnoses, and medical record numbers. The IT team was alerted to the breach on March 28, a week after the hacker had exited the server. PoLP could have helped to prevent the data exfiltration via role-based access control (discussed below).
76% of companies have 3d party roles that allow for full account takeover
Wiz Research Team's Study of 1,300 AWS accounts
Benefits of least privilege
Having explained some real-life scenarios that PoLP could have prevented, let’s examine some of the benefits of implementing PoLP:
Reduced attack surface: The Verizon Data Breach Investigations Report indicates that 82% of data breaches in 2021 resulted from employee and other human-related mistakes/exploitation, circumstances that PoLP effectively combats. By limiting user and software privileges, PoLP ensures that in the event of a breach, only limited parts of and functions within organizations' resources can be accessed, reducing the potential attack surface and preventing lateral movement.
Increased regulatory compliance and improved accountability: PoLP allows for efficient auditing, accountability, and regulatory compliance by enabling organizations to control and track user activities. The ability to implement just-in-time access (that is, granting access at the exact time it is needed and withdrawing it once the specific function has been completed) and least-privilege access reduces the risk of data breaches and allows for easy traceability when security incidents occur. Tracking and tracing facilitate swift remediation and demonstrate organizations’ commitment to protecting sensitive data.
Enhanced data security: Least privilege involves implementing strong authentication mechanisms and encryption to monitor access, detect anomalies, and respond to security incidents effectively. All these are methods used to further secure sensitive data.
Improved productivity and end-user experience: PoLP reduces system downtime, the risk of malware injection (for example, SQL injection), and service disruptions because access to sensitive data and infrastructure is restricted and elevated only when required. The result is improved software availability for IT teams and end users, which in turn leads to greater profit margins.
The Wiz Research team discovered the most common AWS privileges that lead to unintended exposure are: iam:PutRolePolicy, lambda:AddPermission, and AWS ReadOnlyAccess.
Least privilege in the cloud
From virtual machines, orchestration systems, storage buckets, databases, and APIs to remote workers and third-party service providers, highly dynamic variables are a given in every cloud environment. As the cloud evolves, the need to provision and deprovision resources on the fly makes least privilege an essential part of cloud security.
For example, to reduce unauthorized access to sensitive data, enforce least privilege access in object storage environments, such as Azure and AWS. Define granular resource permissions as a first step toward ensuring that users have access only to the specific resources required for their tasks.
Over 90% of cloud security teams were not aware they gave high permissions to 3rd party vendors.
Wiz Research Team's study of 1,300 AWS accounts
Applying least privilege in the cloud also requires understanding PAM boundaries and responsibilities. Most cloud service providers operate under a shared responsibility model, meaning the provider secures the underlying infrastructure while customers secure their applications, data, and user access. It’s critical to understand where cloud providers’ responsibilities end and yours begin.
Finally, to fully secure cloud environments and manage user access, organizations must implement least privilege alongside well-designed identity access management (IAM) security systems, which allow administrators to define roles, permissions, and policies for users and resources.
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A few simple least privilege best practices
Now that we’ve explored the nuances of PoLP, let’s take a closer look at implementation. Here are six best practices for effectively implementing least privilege:
1. Make the most of role-based access control (RBAC)
Implement and regularly review RBAC to assign privileges based on predefined user roles, and update/withdraw these privileges when roles change to enhance your organization’s security posture.
Our data shows that approximately 87% of cloud environments that utilize AKS clusters are using local accounts with Kubernetes RBAC, the least secure authentication and authorization method.
2. Adopt the principle of least privilege by default
Adopt a "default deny" approach to access control. In other words, deny access to resources by default unless access is explicitly authorized. Start with minimal privileges for users and gradually grant additional permissions based on specific needs. Avoid assigning excessive privileges upfront, as more assigned privileges increase the attack surface and exacerbate potential risks.
3. Be careful with administrative privileges
Limit administrative access to trusted employees, and enable just-in-time privilege elevation for them. Implementing multi-factor authentication (MFA) is another way to safeguard administrative access. And it’s always a good idea to monitor activities related to privileged accounts in order to enhance data security and prevent malware injection.
4. Follow the separation of duties principle
Sensitive duties—such as database administration, system configuration, and user access management— should be divided among different individuals to prevent unauthorized actions and lateral movement if a cyberattack occurs. It’s best practice to ensure that no single user has complete authority over important processes.
5. Implement automation, monitoring, and continuous enforcement tools
Leverage IAM solutions, policy-as-code frameworks, and configuration management tools to automate privilege management, thereby reducing human error. Also, establish a robust monitoring and auditing process to track and analyze user activities within your software and in third-party environments. This will enable you to monitor access patterns, privilege usage, and system logs to swiftly detect and put a stop to suspicious behavior.
6. Bolster employee awareness
Educate employees about the principle of least privilege and the importance of access control. Other training topics could include security best practices, social engineering threats, and the potential impact of excessive privileges. Regular training can reduce the risk of employees with privileged accounts falling for phishing links or clicking SQL-attack links, ensuring a more secure software environment.
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Enforce least privilege across your cloud environments
PoLP is the key to avoiding breach-associated consequences, such as business downtime, reputational damage, loss of clientele, lawsuits, and hefty fines. And implementing PoLP doesn’t have to be hard. Wiz's Cloud Infrastructure Entitlement Management (CIEM) solution offers a comprehensive and automated approach to managing user access and privileges in your cloud environments.
With Wiz, it’s easy to define and enforce fine-grained access control policies, conduct regular access reviews, and monitor user activity to ensure compliance with least privilege. Discover the benefits of Wiz's CIEM solution firsthand: Request a demo today.
