Originally published by New Context.
The principle of least privilege, or PoLP, is an information security philosophy that says any user, application, or process should have only the bare minimum network and system permissions necessary to perform its function. When you limit user and application access to only the necessities, you reduce the risk of attackers gaining access to critical systems and files by compromising a low-level account, and you can easily contain the damage to the minimal area the account had privileges to. Implementing the principle of least privilege provides many network security benefits and gives your organization the flexibility to grow while avoiding needless exposure.
Principle of Least Privilege Benefits
Completely changing your network access policies and permissions can feel daunting, but the benefits of PoLP are worth the time and energy. Here are some of the biggest principle of least privilege benefits for your organization.
Minimized Attack Surface
The principle of least privilege narrows the scope of the damage that can be done if a user account is compromised by a malicious actor. If a hacker gains access to a regular user account with limited privileges, the impact of the attack will be confined to the minimal resources that user had access to. In contrast, if an administrator account is compromised, the hacker could potentially cripple your entire network. By keeping your number of administrator accounts to a minimum, you’re decreasing the attack vectors a hacker could use to access sensitive data and business-critical systems.
Greater System Stability
Beyond cyberattacks, PoLP protects your network from human error within your organization. If a standard user has access to programs, databases, or files outside of the scope of their job duties, they could potentially reconfigure or delete something by mistake. By limiting their access to only the resources they need to do their job, you proactively prevent a lot of unintentional, high-impact human error from occurring and provide greater system and network stability.
Limited Malware Propagation
The principle of least privilege prevents the spread of malware on your network. An administrator or superuser with access to a lot of other network resources and infrastructure could potentially spread malware to all those other systems. On the other hand, if your network is bolstered by PoLP, malware infections will likely stay contained on the workstations that initially downloaded the malicious code.
In addition to users, you should also restrict the privileges of your applications. For instance, a SQL injection is a type of hack that involves inserting malicious code into SQL statements. Restricting database accounts to the READ privilege, where appropriate, obviates this line of attack entirely. Failing to limit the privileges of SQL processes and web applications empowers hackers who successfully breach external defenses, allowing them to access and manipulate sensitive data and even control critical systems and infrastructure. Limiting the privileges of your applications will stop these kinds of attacks from gaining any traction on your network.
Improved Data Security
Some of the biggest and most expensive data leaks have been the result of internal actors with access to proprietary information they didn’t need for their job. One of the most high-profile examples of this is Edward Snowden, who was able to leak millions of sensitive NSA files to the media thanks to his elevated privileges. Regardless of how you feel about the NSA or Edward Snowden, we can all agree that his leaks caused a lot of problems for the U.S. government, and those problems could have been avoided if Snowden’s account privileges had been limited to the scope of his job duties.
Following the principle of least privilege will limit the number of people who have access to sensitive data, which decreases the chances of an internal leak and boosts overall data security. As an added benefit, if there is a breach or data leak, advanced restrictions will make it easier to track the source because there will be a limited number of users with access to that data.
Best Practices for Implementing PoLP
Every organization is different, so we can’t tell you exactly how you should implement the principle of least privilege in your environment. However, there are some best practices that every business should keep in mind as they tackle PoLP.
- Audit existing privileges. The first step of implementing the principle of least privilege in your organization is conducting a thorough audit of all existing accounts, processes, and programs to ensure they all have the correct level of permissions.
- Make least privilege the default for new accounts. Moving forward, all new account privileges should be set as low as possible. This should be the default across your whole organization, including IT staff, upper management, and even executives. If a user needs additional privileges later, you can evaluate their specific situation and increase their access level as necessary. This can and should be done immediately, regardless of the status of pending or ongoing security audit; start forming good habits today!
- Elevate privileges on a situational basis. Elevation above least privilege should be evaluated on a case-by-case basis and, if possible, should be temporary. This means users who only need a higher access level for a specific project or limited-time task should receive raised privileges for that specific time period only. Even better, single-use elevation credentials or passwords can provide necessary access while maintaining maximum control over user activity on your network.
- Identify high-level functions to ensure elevations are appropriate. Before you begin restricting the rights of existing accounts, you should identify the specific higher-level functions that require elevated access so you can determine whether or not a user actually needs privilege elevations to complete their tasks. You should also routinely re-identify and re-evaluate these functions, as well as any new processes or job duties that may require elevated privileges, to ensure your organization continues to follow the principle of least privilege even as you grow and change.
- Monitor network activity. To maintain PoLP, you need to monitor and track all user activity on your network, including logins, system changes, and elevation or access requests. Monitoring this activity will help you identify users who have inappropriate privileges, track unusual or suspicious activity, and spot the signs of a breach before it spreads.
- Routinely audit privileges.
It’s important to remember that implementing the principle of least privilege is not a one-and-done process. You will need to routinely audit the privileges granted to users and applications to ensure that all permissions are still appropriate and relevant. Maintaining PoLP is much easier than starting over from scratch, because you are working from a limited list of recently expired credentials that require review. Those smaller review sets can be assessed faster, so staying on top of routine privilege audits will save you time in the long run.
Making the Principle of Least Privilege Work for Your Organization
A privilege management software solution can help automate the process of auditing and changing existing account permissions and creating new least-privileged accounts. Network and cloud monitoring tools also make it easier to track unusual account activity and prevent and stop breaches. The most important aspect of the principle of least privilege is your organization’s security culture, though, so you must train and educate your staff and create an environment where your employees feel comfortable self-reporting security issues and requesting privilege elevations or demotions.