Guard against privilege escalation
Privilege escalation represents a significant security risk, especially in scenarios where permissions are not adequately controlled. Within CloudFormation, it is imperative to architect the system in such a way that each task is associated with its own distinct role rather than inheriting permissions associated with the principal executing the task. This approach ensures that permissions are precisely aligned with the task’s requirements, preventing excessive access.
When implementing task-specific roles, it is crucial to establish a governance mechanism that prevents developers from modifying the IAM roles assigned to these tasks. This is to ensure that developers cannot extend their permissions boundaries by manipulating CloudFormation to perform actions that are beyond their authorized scope. For example, a developer should be able to initiate a stack update, but the execution of that update should be performed by a predefined service role with the exact permissions necessary to carry out the task. This service role is assumed by CloudFormation during the stack operation, which effectively separates the user’s permissions from the stack’s execution context.
By enforcing such a policy, organizations can significantly reduce the risk of privilege escalation. Developers can work within the permissions that are granted to them without the ability to alter the IAM roles that govern the tasks. This approach not only secures the environment against unauthorized access but also aligns with the best practices of least privilege by ensuring that permissions are not just minimized but are also unalterable by those without the authority to do so.
Implement stack policies for resource protection
Stack policies are a means of protecting specific resources within a stack from being unintentionally updated or deleted. These policies provide a layer of governance over stack operations, allowing administrators to define which resources can be modified and under what circumstances.
For example, a stack policy can be crafted to prevent the deletion of an Amazon RDS database instance while allowing updates to its read replica configuration. This ensures that critical components of the infrastructure remain intact and operational, even as other aspects of the stack are iteratively improved. By defining such policies, organizations can safeguard their most sensitive and critical infrastructure elements from disruptive changes.
Concluding our discussion on applying key least privilege principles, let’s transition to the equally vital task of securely managing secrets in IaC.