Detecting Privilege Escalation in Azure AD Using Azure CLI in Cloud Shell
Detecting Privilege Escalation in Azure AD Using Azure CLI in Cloud Shell
Introduction
Privilege escalation is one of the most critical security concerns for any organization that leverages cloud platforms like Microsoft Azure. Azure Active Directory (Azure AD) is the backbone of identity and access management, responsible for controlling access to resources within your Azure environment. When users are able to escalate their privileges—either maliciously or accidentally—it can lead to unauthorized access to sensitive data, systems, or configurations.
In this post, we’ll dive deeper into how to identify if a regular user in Azure AD has escalated their privileges using the Azure CLI within the Cloud Shell. We’ll explore the tools and techniques available to administrators for identifying privilege escalation, analyzing role assignments, and taking corrective actions.
What Is Privilege Escalation in Azure AD?
Privilege escalation occurs when a user gains higher permissions than they should have, often enabling them to perform actions like deleting resources, managing access to critical systems, or viewing sensitive information. In Azure AD, this might mean a user with a basic role like “User” or “Reader” unexpectedly obtains a higher-level administrative role such as “Global Administrator” or “Owner.”
This issue is especially concerning in cloud environments, where an attacker gaining administrative privileges could potentially compromise the entire infrastructure.
Causes of Privilege Escalation:
- Misconfiguration: Unintended role assignments or mismanaged permissions.
- Exploits or Vulnerabilities: Attackers or unauthorized users using system vulnerabilities to elevate their access.
- Human Error: Over-privileged access being granted to users who do not need it.
By monitoring role assignments and activity logs in Azure AD, administrators can detect when a user has escalated their privileges and investigate whether it was authorized.
The Role of Azure CLI and Cloud Shell
Azure CLI is a powerful command-line interface tool that allows you to interact with Azure resources directly from the terminal. Azure Cloud Shell provides an easy-to-use, browser-based interface that comes preloaded with Azure CLI and other necessary tools for managing Azure resources.
The beauty of Cloud Shell is that it is already authenticated with your Azure AD tenant, which makes querying role assignments and reviewing activity logs simple and straightforward without needing to configure additional tools or logins.
Step 1: Understanding Role Assignments in Azure AD
Azure AD uses role-based access control (RBAC) to manage what users and groups can do within Azure resources. Azure AD includes both built-in roles (e.g., Global Administrator, User Administrator) and custom roles that are tailored to your organization’s needs.
In a typical setup, regular users will be assigned low-level roles such as “User” or “Reader,” while privileged roles are typically reserved for administrators. Privilege escalation occurs when a regular user gains higher-level access, such as the “Global Administrator” or “Owner” role.
Key Roles in Azure AD:
- Global Administrator: Full access to all Azure AD resources.
- User Administrator: Can manage users and their roles but doesn’t have full access to all settings.
- Owner: Full control of resources, including access to manage the role assignments.
To detect privilege escalation, the first step is to understand the roles currently assigned to a user and any changes made over time. This can be done using the Azure CLI, which allows you to list the roles assigned to users and track the changes.
Step 2: Querying User Role Assignments
To monitor privilege escalation, you need to query the roles assigned to a user at a specific point in time. You can use Azure CLI to display all the roles assigned to a particular user within your Azure AD tenant. The role assignment query will return the roles granted to a user.
By running this query, you can verify whether a user has been assigned a role that grants elevated privileges. If a regular user, such as one with a “User” or “Reader” role, has been assigned a higher-privileged role, such as “Global Administrator,” this would signal a potential case of privilege escalation.
Step 3: Investigating Recent Role Changes
In many cases, privilege escalation happens when roles are reassigned to users or groups. It’s crucial to monitor any recent changes to role assignments, as they might indicate suspicious activities or unauthorized privilege increases. You can query all role assignments across your Azure AD directory and filter for recently created assignments.
By listing the roles assigned to users, you can identify when an elevated role was assigned and whether the user was authorized to receive it. Pay particular attention to assignments made to users with initially lower privileges. If a user suddenly receives a high-privilege role such as “Global Administrator” or “Owner,” it’s time to investigate.
Filtering Role Assignments:
You can filter results based on timestamps, such as querying for roles assigned in the last 24 hours. This helps you detect any new or unapproved privilege assignments in real time, giving you a proactive approach to managing role escalation.
Step 4: Analyzing Azure AD Activity Logs
Azure Activity Logs provide a detailed record of all operations performed within your Azure AD environment. These logs are crucial when you want to investigate the who, what, and when of role assignments, especially when you suspect a user has escalated their privileges.
To identify whether a user has gained elevated access, you need to look at the activity logs related to role assignments. This includes reviewing logs for actions like role creation or updates, especially those where a higher-privileged role was assigned.
Filtering Activity Logs:
In the activity logs, look for events where “role assignments” were modified, and examine the user who made those changes. If the change was performed by a high-level administrator (such as a Global Administrator), it might be a legitimate reassignment. However, if the change was made by a lower-level user, or an unapproved administrator, this is a red flag.
You can filter activity logs by operation name, focusing specifically on actions such as role assignment or modification. By cross-referencing this with the role assignments you previously queried, you can confirm whether any escalations are legitimate.
Step 5: Using Azure Monitor for Continuous Auditing
Privilege escalation isn’t always an isolated event. As part of a comprehensive security monitoring strategy, it’s important to implement continuous auditing and real-time alerts for any suspicious activity related to role assignments.
Azure Monitor provides a set of tools that can help you set up automated alerts and triggers based on specific actions, such as a user being assigned an elevated role. By creating an alert rule for role assignments that fall outside of your standard security policies (e.g., assignment of high-level roles to non-administrative users), you can quickly detect and respond to any suspicious activity.
This approach helps in ensuring that privilege escalation attempts are immediately flagged and investigated, preventing any unauthorized access from going unnoticed.
Step 6: Corrective Actions in Case of Privilege Escalation
If you detect unauthorized privilege escalation, it’s critical to take immediate action. The first step is to revoke the unauthorized roles. You can remove a user’s elevated privileges using the Azure CLI command designed for role assignment removal.
Once the inappropriate role is removed, investigate how the escalation occurred. Did the user exploit a configuration weakness, or was the change the result of human error? Identifying the root cause is key to ensuring that similar incidents do not happen in the future.
If you believe that the escalation was part of a broader security incident, it’s also important to notify your security team, review activity logs for signs of malicious activity, and take any necessary steps to secure your environment.
Step 7: Preventing Future Privilege Escalation
Once you’ve addressed the immediate threat, you should focus on preventing future privilege escalation attempts. This can be achieved by implementing the following measures:
Best Practices:
- Role-Based Access Control (RBAC): Use RBAC to ensure that users are only assigned roles that are essential for their job functions. The principle of least privilege should be applied at all times.
- Just-in-Time Access: Implement Azure Privileged Identity Management (PIM) to enforce just-in-time access to high-level roles, requiring users to request elevated access for a limited time and only when necessary.
- Conditional Access Policies: Apply Conditional Access policies that restrict administrative actions based on factors like the user’s location or the device they are using. This ensures that elevated roles are only granted under safe conditions.
- Multi-Factor Authentication (MFA): Enforce MFA for all users, especially those with elevated privileges. This adds an additional layer of security, making it harder for attackers to escalate privileges.
Conclusion
Privilege escalation in Azure AD can pose significant risks to your organization’s security. Using Azure CLI in the Cloud Shell, administrators can quickly detect unauthorized role changes, investigate potential escalations, and take corrective action. By combining role monitoring, activity logging, and automated alerts with best practices like RBAC and PIM, you can minimize the risk of privilege escalation and ensure that only authorized users have access to high-level roles.
Detecting and responding to privilege escalation in real time is crucial to maintaining the integrity of your Azure environment and protecting your organization’s sensitive data and resources.