In IT, the principle of least privilege (PoLP) refers to the concept that any process, program or user must be provided with only the bare minimum privileges (access or permissions) needed to perform a function. For instance, if a user account has been created for accessing database records, it need not have admin rights. Also, a programmer responsible for updating lines of legacy code can do so without access to the company’s financial records.
PoLP is a cybersecurity best practice and often considered a critical step for protecting privileged access to a businesses’ high-value assets and data (including customer/employee records). Since this principle extends beyond the scope of human access, it is also applicable to systems, applications and connected devices that require certain permissions or privileges to perform a task.
What Least Privilege is Used For
Did you know that two of the most infamous data breaches on record, namely the ones at Home Depot[i] and Target[ii], occurred due to a compromise of their network credentials? In both the cases, hackers used privileged accounts to access critical business data and private records of customers. Taking cue from the breaches in the past, you need to understand that your informational security professionals and network managers must deploy security strategies for users and applications to perform critical functions within the network.
For ensuring efficient enforcement of the principle of least privilege, you need to devise a strategy to manage and secure your privileged credentials centrally and deploy flexible controls to strike a balance between your operational and end-user needs and your compliance and cybersecurity requirements.
Securing Your Business
The Vectra 2020 Attacker Behavior Industry Report[iii] highlights that privileged access is a key aspect that hackers leverage for lateral movement in cyberattacks. They use these privileges to gain access to the most critical assets that a business relies on.
PoLP is an efficient cybersecurity strategy that can be used to restrict unauthorized access of data from the different levels within your IT environment including applications, end users, systems, networks, databases, processes and so on. You can grant permissions to your users to execute, read or write only those resources or files that they need to perform their job. Additionally, you can restrict access rights for devices, processes, systems and applications to privileges required to carry out authorized activities.
Managing Access Levels
In some cases, the assignment of privileges is done on role-based attributes such as the business unit, time of day, seniority and other special circumstances. Some examples of role-based privileges include:
Least privileged user accounts —These are standard user accounts that operate with a limited set of privileges. Under normal circumstances, most of your users should be operating under these accounts, 90 to 100 percent of the time.
Superuser accounts — These are essentially admin accounts that are used by specialized IT users and often come with unlimited privileges. In addition to the read/write/execute privileges, these accounts have the permission to execute systemic changes in your IT network.
Guest user accounts — These accounts are created on a situational basis and often have the least number of privileges — lower than those of the standard user accounts.
Managing Third-Party Vendor Risk
An interesting thing to note about the Target data breach is that it started with the hackers gaining access to nearly 70 million customer accounts through an HVAC contractor who had access to Target’s network and the permission to upload executables.[iv] What this implies is that you must not ignore third-party vendor risk management. Apart from your internal users, you must also implement principle of least privilege for your third-party vendors as they can be a major security risk for your business. Limiting third-party vendor access to your critical data can be an efficient strategy towards minimizing the associated risk.
Benefits of Principle of Least Privilege
We have rounded up a list of benefits of leveraging the principle of least privilege for your business. Read on:
Diminishes the Attack Surface
As mentioned earlier, the role of an HVAC contractor was critical to the Target data breach. Given the fact that the third-party vendor had elevated privileges, one can safely say that Target failed to implement PoLP, which consequently created a broad attack surface for the hacker to leverage.
Under PoLP, restricting privileges for your applications, processes and users significantly diminishes the attack surface and limits the ingresses and pathways for exploit.
Reduces the Impact of Breaches
By implementing PoLP, you can significantly reduce the impact of a breach that might occur as a result of unauthorized or unwanted use of network privileges. For instance, if a user account that has only limited privileges is compromised, the scope of catastrophic harm is relatively low.
Reduces Malware Propagation and Infection
Hackers usually target applications and systems with unrestricted privileges. As one of the most common web applications cyberattacks out there, a SQL injection attacks by inserting malicious instructions within SQL statements. The hacker can then enhance his privileges and acquire unauthorized control over your critical systems. However, by implementing PoLP, you can efficiently stunt and contain such malware attacks to where they first entered your system.
Ensures Superior Data Security Capabilities
In addition to eliminating any security flaws on the periphery of your business, you also need to focus on minimizing the risk of proprietary data thefts and insider leaks. That being said, it is imperative to monitor and control the activity of your authorized users to reinforce your cybersecurity stance.
Since PoLP restricts privilege elevations as well as the number of users that are given access to confidential information, it inherently enhances the security of your critical data.
PoLP Best Practices
There are certain best practices that you must follow to efficiently implement PoLP in your security policies.
Here is a list:
- For starters, you must conduct a privilege audit for all your existing programs, processes and user accounts to make sure that they have only the bare minimum permissions required to do their jobs.
- Make sure that you start all your user accounts with privileges set to the lowest possible level. Implement least privilege as the default for all your existing as well as new user accounts, applications and systems.
- You must elevate account privileges as needed and only for a specific time period that is required to do the job. An efficient strategy to provide the required access while also maintaining control is using one-time-use credentials and expiring privileges.
- Keep track of all the activity on your network including access requests, systems changes and individual logins. Having a comprehensive understanding of who is operating on your network and what they are doing is critical to maintaining control over who can access what.
- Maintain a management platform that allows flexibility to securely elevate and downgrade privileged credentials.
- Conduct regular audits to check if there are any old accounts, users or processes that have accumulated privileges over time and analyze whether or not the elevated privileges are still relevant
According to PoLP, organizations should operate under the zero-trust framework by not blindly trusting anything within or outside their network and verifying everything before granting permissions for access.
Implement PoLP across your IT environment today to strengthen your cybersecurity posture. Don’t know how? Contact us now to help you understand how you can implement and leverage the powerful capabilities of PoLP.
Article curated and used with permission.
[i] https://www.webtitan.com/blog/cost-retail-data-breach-179-million-home-depot/#:~:text=The%20Home%20Depot%20data%20breach,one%20of%20the%20retailer’s%20vendors
[ii] https://arxiv.org/pdf/1701.04940.pdf#:~:text=1%20INTRODUCTION,of%20personal%20information%20were%20stolen
[iii] https://www.securitymagazine.com/articles/91830-surge-in-attacker-access-to-privileged-accounts-and-services-puts-businesses-at-risk
[iv] https://krebsonsecurity.com/2014/02/target-hackers-broke-in-via-hvac-company/