The cybersecurity principle of least privilege is an information security framework that aims to provide users with the minimum level of access or permissions required to perform their tasks. IT security, as a whole, is a complex, multifaceted discipline, and least privilege has emerged as one of the most essential cybersecurity best practices to protect access to mission-critical enterprise assets. Least privilege is not just limited to human access. It also extends to applications, automation tools, and connected devices (such as IoT endpoints) that require access to privileged systems within the corporate network.
Suppose a bank manager has three employees reporting to them; a copywriter, a clerk, and a legal advisor. The copywriter is given access to the printer room so that they may print agreements, policy documents, and other important paperwork. The clerk is given access to the filing cabinet and the printer room. The legal advisor would probably be given access to the printer room and the filing cabinet, but is also given permission to enter the bank manager's office on request. Essentially, the manager has assigned the least amount of privileges required by the employee belonging to that specific role, and only the manager has access to the bank's vault. This philosophy of assigning the least privileges to users based on what their role demands is the principle of least privilege.
To enforce least privilege simply means to assign the minimum required privileges to perform a job. Effective enforcement of least privilege includes implementing a fine-grained, centralized access control mechanism across the enterprise network—one that balances cybersecurity and compliance requirements while also making sure there's no impediment to end users' daily operational requirements.
Least privilege, at its core, aims to condense an organization’s attack surface by reducing the number of access pathways leading to privileged systems. A common approach adopted by organizations to curb excessive privileges is the revocation of administrative access from business users. However, IT teams often need to re-grant privileges to end users whose day-to-day operations involve accessing privileged systems. In such cases, privileges are re-granted and rarely revoked, resulting in a gradual accumulation of access rights—beyond what is required. This practice permeates through the organization across various levels of users, resulting in a security situation called privilege creep that can potentially exacerbate the problem of unauthorized access. When enterprises overlook such intricate privilege accumulations, they become susceptible to exposing their critical accounts to privilege creep.
Privilege creep is the proliferation of privileges beyond a user's access level. Privilege creep often occurs when the IT admins are generous while assigning privileges to users to escape from the bureaucracy of IT support. Another plausible and common reason privilege creep happens is if a team forgets to remove the privileges of old or temporary users.
Typical examples of privilege creep include if an individual's job description is updated and the individual's old privileges are not revoked even after the period of transition, or if an individual needs additional privileges temporarily to perform a task outside their usual job function and the organization does not revoke these additional privileges after the job is complete.
The dangers of privilege creep can be mitigated by enforcing least privilege across all employees in the enterprise. Once the job is done, the access is immediately revoked, closing the door on potential vulnerabilities and standing privileges. In short, enforcing the principle of least privilege revolves around the zero trust security model, i.e., the idea that every employee, irrespective of their geographical location, has the potential to fall victim to threat actors or even become one themselves.
Let's look back to the bank example we saw earlier. Why is it that the manager had to implement least privilege in the first place? First, not all employees need access to every room, especially important places like the vault, which holds customer information and wealth. Second, the manager trusts employees to perform tasks that fall under the purview of their role but also needs timely verification if they are to perform tasks that require entrance to rooms that fall outside their default access.
Now similarly, through the use of a PAM solution that incorporates zero trust and the principle of least privilege, IT admins can enforce access restrictions on users to limit their privileges to those of the user role's requirements. Any PAM solution's modus operandi is based on the cybersecurity principle of least privilege. A PAM solution offers settings for IT admins to configure their own restrictions and map least privilege to users based on their roles.
This is essentially how zero trust fuels the implementation of the principle of least privilege—through role-based access control.
Suppose there is an employee that works with critical resources on an IT team. They are expected to send access requests every time they log in to the system. This request is then approved by the IT admin. Once their task is completed for the day, the user is logged out of the resource and is expected to raise another request if they require access to the system.
Another plausible example could include different teams of employees that are expected to access a critical resource. However, only one person from each team is given access to this resource, reducing the exposure to multiple identities and thus mitigating the threat of unauthorized access.
In an enterprise scenario, privilege escalation attacks take progressive control of the system access functionalities in the following ways:
The least-privilege model eliminates administrative access and standing privileges, which means the number of access pathways to critical enterprise resources is also considerably reduced, making the overall attack surface smaller.
Because malware requires elevated privileges for execution, enforcing least privilege on endpoints helps curb the propagation of malicious software. Even if an attack occurs, the malware will not be allowed to run without admin privileges, substantially reducing the potential damage.
By removing administrative access for end users and enabling policy-driven, just-in-time (JIT) privileged access, organizations can facilitate smoother access workflows, increase employee productivity, and keep IT help desk calls in check while also curtailing threats resulting from excessive privileges.
Least-privilege enforcement helps organizations establish transparency over who accessed what and when, creating an audit-friendly environment. It also comes in handy for meeting various industrial and federal regulatory requirements that demand enterprises implement strict access control policies to bolster data stewardship and system security, such as HIPAA, PCI DSS, SOX, the GDPR, and the CCPA.
Here are some of the reasons why enterprises need to include privileged password management as part of their IT security strategy. These following best practices can be introduced to any existent working security model using a PAM solution.
Start by conducting a thorough privilege audit to ascertain all privileged accounts currently in use and the type of access they provide. This includes all local and domain administrator accounts, privileged passwords, SSH keys, service accounts, and credentials hard-coded in DevOps pipelines for human and non-human entities.
Remove local administrator privileges on endpoints and the default standard privileges for all users, but include provisions to extend elevated access for specific applications depending on user roles. Remove administrative access rights to all servers within the network, and make every user a standard user by default.
Compartmentalize both user privileges and privileges across various applications, systems, and processes, and grant only the minimum required privileges for all types of users. This helps restrict unauthorized access and prevents lateral movement.
Assign JIT controls for domain and local accounts, and extend temporary elevated privileges when requested by users. Automatically revoke permissions after a set time period. Here, the actual credentials are not exposed to the user while sufficient access is provided for the amount of time required to complete the task at hand.
Mitigate the possibilities of privilege abuse by taking the embedded credentials in DevOps pipelines, RPA systems, and other connected devices and replacing them with APIs that allow retrieval of credentials from password vaults equipped with request-release workflows. Immediately rotate privileged passwords and keys after every access to invalidate credentials that might have been recorded by key logging tools.
Make sure your least-privilege policies extend beyond physical boundaries to your cloud entitlements, the pool of remote employees, contractors, vendors, and all remote access sessions launched.
Consistently review all user activities and record a video of privileged sessions for clear accountability. Incorporate user trust scoring to detect anomalies in real time and terminate any suspicious user activity.
PAM360 is the ultimate amalgamation of ManageEngine's PAM solution suite.
PAM360 offers various services including password request-release workflows, JIT, and role-based access control.
Similar to the example we saw above, PAM360 allows IT admins to set up request-release workflows with customizable settings that will dictate how a privileged user may access a critical resource. Through such workflows, PAM360 forces a 4-eye principle check over any password request approval process.
PAM360's JIT privilege allocation feature allows IT admins to temporarily grant access to users by enabling access controls. This temporary elevation of privileges is broadly termed as privilege elevation and delegation management.
Role-based access control is the limitation of privileges to users based on the role they perform in the organization. Through multiple customizable roles available in PAM360, IT admins can segregate users into admin-based and user-based roles. They can further limit the extent of their privileges and select which user is given which privilege.
Talk to our experts to understand how you can deploy the cybersecurity principle of least privilege in your organization's IT workflow and security practices with PAM360.