What is least privilege – and why do you need it?

What is the principle of least privilege (PoLP)?

The principle of least privilege is a cybersecurity concept that reduces an organization’s attack surface by granting access on a strictly as-needed basis. Users’ access rights are limited to those needed to do their job or complete a specific task. The objective of least privilege access is to reduce attack surfaces and blast radiuses by minimizing lateral movement and, thus, the damage that can be done in the event of unauthorized access.

Least privilege access is applied to all read, write, and execute functions that users require to do their jobs. It controls rights for human and non-human users (e.g., applications, backup systems, databases, Internet of Things (IoT) devices, operating systems, and servers).

With least privilege, access rights can be fairly broad to granular. In some cases, least privilege rights are based on attributes associated with a user’s role within an organization. In other cases, least privilege access is tied to location or time of day. In addition, least privilege can extend to the specific systems or applications a user can access.

The three core elements of least privilege access are:

1. Identity authentication
   Enforcing least privilege access by confirming users that attempt access are verified as authorized
2. Device health
   Using least privilege access to protect users from becoming tainted by compromised devices by assessing device health before granting access
3. Segmentation
   Implementing granular segmentation for both network and user-to-application access to enforce the principle of least privilege

How does access control relate to least privilege access?

Access control and the principle of least privilege are closely related concepts. Access control is a broader term that covers the processes and technologies used to manage and regulate who or what can view, use, or manipulate resources in a computing environment. Least privilege access is a specific strategy or guideline applied within the framework of access control to enhance security and minimize risk exposure.

The following are examples of how access control and least privilege access are related.

Attribute-based access control (ABAC)
With ABAC, access decisions are based on attributes or characteristics, such as the department, role, time of access, and the sensitivity of the data. This allows for more granular enforcement of least privilege access based on a wide range of operational contexts and data classifications.
Automated management tools
Privileged access management (PAM) systems are used to manage, control, and monitor least privileged access and sessions for administrators and high-level users. PAM solutions help enforce least privilege access by providing just enough access to perform a task and just-in-time privileges, which keeps the standing privileges to a minimum.
Monitoring and logging
Access control systems monitor who accesses what data and when providing audit trails that help ensure that least privilege access is being enforced and that any exceptions are quickly identified and addressed.
Dynamic access adjustments
Dynamic and conditional access control systems can adjust permissions dynamically based on the current context or observed risk levels. This adaptability helps maintain least privilege access under varying conditions to provide maximum security without interfering with operations.
Implementation framework
Least privilege access acts as a guiding principle for setting up access control mechanisms. When designing access control policies, employing the principle of least privilege means that each user, program, or system entity is granted the minimum level of access necessary to perform its functions.
Layered defense strategy
Access control systems typically employ a layered defense strategy, incorporating multiple security mechanisms such as firewalls, authentication protocols, encryption, and intrusion detection systems. Least privilege access complements these mechanisms by ensuring that even if one layer is breached, the amount of accessible resources remains minimal, minimizing the potential impact of an attack.
Regular reviews
Access control systems facilitate regular reviews and recertifications of user rights, which is important for preventing privilege creep, where users accumulate unnecessary access rights over time, typically as they change roles or take on new responsibilities. Regular audits and the reevaluation of privileges ensure that access rights remain aligned with current needs and the privilege access rules.
Role-based access control (RBAC)
Access control systems often use RBAC to access based on specific roles and job requirements. Each role is configured with the least privilege access permissions to enable users to perform their job functions.
Security posture enhancement
Access control provides the infrastructure and tools to enforce various security policies, including authentication, authorization, and accountability. Applying least privilege access within this infrastructure significantly enhances an organization’s security posture by limiting the attack surface and potential damage from an attack.

What is least privileged role-based access?

Least privileged role-based access facilitates access restrictions by ensuring that users’ rights are strictly aligned with the specific duties of a role to minimize potential security risks. Establishing least privilege role-based access starts by meticulously defining the roles within an organization based on job requirements and responsibilities. Each role is then assigned only those permissions essential to perform its functions.

Implementing least privilege role-based access simplifies the management of permissions, making it easier to audit and enforce security policies. It also reduces errors in permission assignments, decreases the risk of internal threats, and simplifies the process of onboarding new employees or transitioning existing employees to new roles.

Considerations when implementing least privilege role-based access are:

1. Avoid creating overly specific roles, which can lead to an unmanageable number of roles.
2. Consider systems that allow for dynamic access control to enable conditional and temporary access rights, which can be granted as needed and automatically revoked.
3. Regularly review roles and their corresponding access rights to adjust for changes in job functions, compliance requirements, or organizational structure.
4. Take care to analyze job functions to ensure that roles are designed around the needs of the organization and do not include unnecessary access privileges.

What is an example of the principle of least privilege?

The principle of least privilege is illustrated in the following examples of its use in a typical corporate environment.

1. A financial analyst is given access to accounting software, financial reporting tools, and budget spreadsheets but not prospective sales numbers.
2. A human resources manager has access to employee records, payroll information, and recruitment tools but not financial records.
3. A payroll clerk is granted access to payroll processing software but not to other financial systems or databases that are irrelevant to their role.
4. An IT support staff member will have permission to access the network and server management tools but not the financial or human resources databases.

Definition of privileged accounts

A privileged account is any user account, human or non-human, with more access and rights than ordinary users. Privileged accounts, often referred to as administrator or admin accounts, can be associated with a variety of admin and non-admin users, including:

1. Auditors
2. Third-party or fourth-party contractors
3. Employees
4. Non-humans, such as:
5. Vendors
6. Database administrators
7. Helpdesk experts
8. IT administrators
9. Security teams
10. System and application administrators
11. Applications
12. Application-to-application (A2A)
13. Backup systems
14. Databases
15. Internet of Things (IoT) devices
16. Machine-to-machine (M2M) servers
17. Operating systems
18. Services accounts

Least privilege is particularly important for privileged accounts, because of the access rights granted to them. Since most attack vectors leverage access to execute their crimes, privileged accounts are often targeted as they offer greater lateral movement opportunities and facilitate escalation tactics as part of an attack chain.

Using least privilege access controls for privileged accounts allows them to be safely used to perform their duties with limited risk from exploitation. Special administrative or elevated privileges that privileged accounts have include:

1. Accessing sensitive information, such as personally identifiable information (PII), protected health information (PHI), legal documents, employee information, customer information, government files, and trade secrets
2. Extended, sometimes global, rights within the IT resources (e.g., applications, databases, devices, servers, and systems)
3. Installing or removing software
4. Modifying configurations for applications, systems, or devices
5. Upgrading or modifying operating systems
6. User administration (e.g., add, remove, and disable accounts, or modify permissions)

Privileged access and the cloud

Cloud deployments depend on access controls to manage workloads. Cloud instances require support to ensure user access is authorized, as instances, runtime, and resources are based on a permissions model.

Because cloud computing is highly dynamic, layers of privileges are often provisioned, especially in multi-cloud environments.

Least privilege access can address the many issues related to cloud deployments by restricting access based on need. It mitigates the issues related to overprovisioning and reduces the attack surface for all cloud instances.

Common threat vectors to privileged access

Following are some of the many threat vectors that target privileged accounts.

Privilege escalation

Privilege escalations allow attackers to propagate attack vectors on target systems for a number of reasons, including to:

1. Deploy malicious software on a target system
2. Gain root access to a target system or an entire network
3. Modify security settings or privileges to elevate access privileges
4. Procure access to other connected systems, applications, or data

What happens with a privilege escalation attack depends on whether a horizontal or vertical attack is perpetrated.

1. Horizontal privilege escalation
   With a horizontal privilege escalation attack, the perpetrator starts with one account, then uses that to gain access to the rights of other accounts with comparable privileges. These accounts can be humans or machines.
   
   Referred to as an account takeover or lateral movement, horizontal privilege escalation attacks typically target lower-level accounts that are often lacking enhanced security protections.
   
2. Vertical privilege escalation
   Also referred to as a privilege elevation attack, vertical privilege escalation attacks increase access privileges beyond those the user (e.g., a person, application, system, or device) already has. The attacker usually has to execute several steps to bypass or override privilege controls, exploit vulnerabilities, or obtain privileged credentials.
   
   Among the techniques used as part of a vertical privilege escalation attack are taking advantage of common weaknesses and flaws, such as:
3. Overprovisioning of privileges
4. Lack of awareness of privileged accounts
5. Hardcoded and embedded credentials
6. Shared admin accounts
7. Weak passwords
8. Misconfigurations

Password hacking

The growing requirement for strong passwords results from a rise in successful password hacking. Cybercriminals are becoming increasingly adept at developing and using programmatic techniques and automation to determine users’ login credentials.

In addition, if the account holder reuses passwords between resources, the risks of password guessing and lateral movement dramatically increase. Imagine a person who uses only one or two base passwords everywhere—for all their digital presence and privileged accounts. Unfortunately, this is a frequent occurrence.

Shoulder surfing

A low-tech and sometimes no-tech way of procuring users’ login credentials is shoulder surfing, whereby a cybercriminal watches users enter usernames, passwords, and personal identification numbers (PINs). They can also access users’ credentials by getting them from notes left on desks, which is more common than many organizations expect.

Password changes and resets

Cybercriminals routinely take advantage of password change and reset functions in many applications and systems. This is a ripe target for attackers, because users tend to make common mistakes, such as:

1. Communicating new passwords verbally so that they can be overheard
2. Creating passwords that are so complex that users write them down and save them
3. Resetting passwords via email or text message and keeping the new credentials
4. Using the same generic password when resetting users’ accounts (i.e., by helpdesk teams)

Malware

No review of threat vectors is complete without malware. Among the types of malware used to target privileged accounts are:

1. Adware
2. Bad bots
3. Bugs
4. Ransomware
5. Rootkits
6. Spyware
7. Trojan
8. Viruses
9. Worms

Social engineering

Always an effective tool for cybercriminals, social engineering attacks are often used to compromise privileged accounts. Common social engineering ploys include:

1. Pharming
2. Phishing
3. Scareware
4. Spear phishing
5. Vishing
6. A watering hole

Least privilege access challenges

At its root, least privilege is about providing users with as little access as possible. This means restricting access and removing access when it is no longer needed. Both seem prudent, but these two fundamental components of least privilege access cause challenges.

Minimal access

With least privilege, administrators handle granting access, which can be a nuanced process. In many cases, administrators do not know specifically how much access is actually required, and may “round up,” and grant users more access than they actually need to minimize the hassle of having users request additional access. However, if insufficient access is granted, users suffer from productivity loss from not being able to perform their tasks and time spent requesting additional privileges.

Expiration of access

Another least privileged access challenge is changes in users’ tasks. Least privilege access dictates that it should be set according to the needs of the task and when access is no longer needed, it should be terminated. However, during the course of a project, requirements may change, and timelines may be extended as a result. When access is terminated based on preset determinants, productivity and morale can suffer.

Least privilege access benefits

Following is a review of the benefits that least privilege access can provide to organizations. These benefits also demonstrate why least privilege access has become integral to many security portfolios. By restricting what users can access, least privilege prevents a number of malicious and accidental activities that can compromise security.

1. Bolsters system stability by limiting the number of users making changes or updates
2. Contains malware to limit its impact by keeping its ability to propagate to a minimum, as most users only have limited access to other resources that could be compromised
3. Controls access to data to limit users’ ability to view, edit, share, or extract data from systems and applications
4. Reduces helpdesk calls by giving users the access they need to complete their designated tasks
5. Decreases the chances of an internal leak of sensitive information
6. Enhances data security by limiting the number of people who have access to sensitive data
7. Helps keep superuser accounts and privileged administrator accounts and access to a minimum
8. Improves audit readiness and the scope of audits
9. Improves user productivity by providing direction for how access is provisioned and managed
10. Make it easier to track the source of a cyber attack or data breach, because there are a limited number of users with access to that data
11. Minimizes the points of entry available for cybercriminals to exploit by reducing the user access attack surface
12. Mitigates the impact of human error by limiting users’ access to systems, applications, and data that could be inadvertently changed or deleted
13. Protects against privilege escalation attacks by limiting users’ privileges, including superusers and administrators
14. Provides guidelines and processes to manage the elevation of access privileges
15. Reduces the downtime and losses that result from a cyber attack or data breach
16. Restricts access to applications, systems, and devices to prevent unauthorized configuration or access changes
17. Supports compliance with regulatory mandates that require protections against data breaches and cyber attacks that could compromise data and systems

Least privilege access best practices

The implementation of least privilege access will vary by each organization to accommodate their unique requirements. However, the following are seven best practices that have proven to be effective for many organizations.

Conduct regular audits

The success of least privilege depends on access staying current. Users’ requirements, roles, and employment statuses continuously change.

A key part of enforcing least privilege access is having processes in place to audit usage and requirements and making necessary adjustments routinely. These least privilege audits should review all existing accounts, processes, and programs to ensure they have the minimum permissions and that access is still needed. This prevents cases where older users, accounts, and processes accumulate privileges over time, whether they still need those things or not, and flags inactive accounts.

Elevate privileges for a limited time

Least privilege allows for access to be elevated. However, it is recommended that this is temporary.

Any access beyond the established least privilege should be restricted by time or number of logins. The privileges granted must be temporary whenever a user needs to raise the level of access for a specific project. This elevation in least privilege access can be restricted by time (e.g., a month), single-use access until a project is complete, or until there is a change in the user’s role.

Extend least privilege access on an as-needed basis

Least privilege access should be elevated on a case-by-case basis. Before a user is granted elevated privileges, a thorough review of access requirements should be conducted.

Identify high-level functions that require elevated least privilege access

Avoid productivity losses and user frustration by identifying users that require elevated access. Organizations can take care not to restrict authorized users by deploying a blanket approach to access, then adding privileges. This will be necessary in some cases, but taking time to grant elevated access where it is appropriate proactively is important.

Start with least privilege access for new accounts

Establish least privilege access requirements for the types of users in the organization. When provisioning new accounts, follow least privilege guidelines and elevate access as need is demonstrated.

Starting with a default of least privilege facilitates implementing and managing a least privilege access protocol for IT.

Note that least privilege access should take compliance requirements into consideration.

Track all user actions

Monitor and track all user activity (e.g., elevation or access requests, logins, activities, and system changes) to detect any instances of overprovisioning. This important function of least privilege access ensures that misappropriation of privileges is rectified quickly to minimize risk and reduce threats.

Least privilege FAQ

Following are answers to some frequently asked questions about least privilege.

What is PoLP?

PoLP stands for the principle of least privilege. This security concept mandates that users, systems, applications, and processes should be granted the minimal level of access—or the least amount of privileges—necessary to perform their tasks or functions. By implementing least privilege access, organizations can significantly reduce attack surfaces by ensuring that even if an account or system is compromised, the ability of the threat to cause harm or access sensitive information is restricted to a limited area.

What is least minimum access?

The terms least minimum access and least privilege access are often used interchangeably in the context of cybersecurity. However, least privilege access is the more commonly used and recognized term, and least minimum access is not a standard industry term.

How do organizations implement least privilege access?

Organizations typically implement least privilege access in ways including the following.

1. Apply least privilege access to development environments by restricting access to production data and critical infrastructure.
2. Conduct a role-based access control (RBAC) assessment to identify the various roles within the organization based on job functions and responsibilities and confirm that each is assigned least privilege access.
3. Create and enforce an application whitelist to extend least privilege access to approved applications.
4. Default new account and system to access the least amount of privileges necessary.
5. Educate and train employees.
6. Employ segregation of duties to divide tasks among different individuals to prevent any single person from having too much control or access.
7. Extend least privilege access beyond the network or system level to include applications, databases, and other software tools.
8. Implement access control mechanisms to enforce least privilege access, such as RBAC, ABAC, and PAM systems.
9. Implement systems that grant privileges on a temporary, as-needed basis.
10. Limit physical access to critical infrastructure (e.g., data centers) to those whose roles explicitly require it.
11. Provide continuous training on the importance of least privilege access and secure access protocols.
12. Regularly review and update access rights to ensure they still align with current roles and responsibilities.
13. Require multi-factor authentication (MFA) to add layers of security that enforces least privilege access rights to verified users.
14. Use logging and monitoring tools to track access to sensitive systems and data, enabling the detection of unusual activities that could indicate a breach or abuse of privileges.

Importance of least privilege access

When strategically implemented, least privilege access strikes the elusive balance between usability and security to protect critical data and systems. Least privilege is a cybersecurity approach that minimizes the attack surface, prevents cyber attacks, enhances operational security, and reduces the impact of human error.

Least privilege access is an effective security approach to defend all types of users and use cases in today’s hybrid enterprise environments—from employee and third-party access to applications and operating systems. While it requires continuous monitoring and updates, least privilege access can be part of the line of defense for any organization.

How mature is your identity security strategy?

Discover the 5 horizons of identity security.