Hidden Dangers in Default AWS IAM Roles: What You Need to Know About Cloud Security Risks

In today’s cloud-driven world, Amazon Web Services (AWS) remains a dominant platform powering countless enterprises. However, recent findings by cybersecurity researchers have uncovered significant risks lurking in AWS’s default Identity and Access Management (IAM) roles. These roles, often created automatically during setup, come with overly permissive access rights that could give attackers a dangerous foothold. Without proper oversight, such default roles enable privilege escalation, lateral movement across AWS services, and potentially full account compromise. Understanding these vulnerabilities is essential for cloud users aiming to safeguard their infrastructure.

the Risk: Overly Broad Default IAM Roles in AWS

Aqua Security researchers Yakir Kadkoda and Ofek Itach revealed that several AWS services automatically generate IAM roles with overly broad permissions, most notably granting full access to Amazon S3 storage. These default roles—created by services such as SageMaker, Glue, EMR, and Lightsail—often include the AmazonS3FullAccess policy, which allows complete read/write capabilities to every S3 bucket within an AWS account.

This broad access poses a serious security threat. Attackers who gain minimal initial access to such a role can exploit it to perform administrative actions across AWS services. They can bypass isolation boundaries, escalate privileges, and move laterally to compromise multiple services and data repositories. Unlike traditional “bucket takeover” attacks, where adversaries rely on predictable bucket names, these roles allow attackers to directly search and manipulate buckets and related resources without guessing names.

A hypothetical attack could involve uploading a malicious machine learning model to a public repository like Hugging Face, then importing it into SageMaker to trigger arbitrary code execution. From there, attackers might compromise Glue jobs, steal credentials, and inject malicious templates into CloudFormation, escalating control over the entire AWS environment.

AWS has since updated these default policies to reduce risk, but organizations must proactively audit and limit role permissions rather than rely on default settings. The research highlights a critical need for tighter scoping of service roles and continuous vigilance in cloud security management.

What Undercode Say: The Imperative for Proactive Cloud Security Management

Cloud environments are inherently dynamic, and their security depends heavily on meticulous access controls. The discovery of risky default IAM roles underscores a vital truth: default configurations are rarely secure by design. Cloud architects and security teams must treat these findings as a wake-up call to reassess how roles and permissions are granted.

Default roles with broad access such as AmazonS3FullAccess introduce a silent but powerful attack surface. Since these roles are automatically created or recommended during service setup, many organizations may not even realize their existence or the risk they pose. This invisibility can lead to a false sense of security, especially if audit procedures are irregular or superficial.

What makes these roles particularly dangerous is their ability to break isolation boundaries. AWS services like SageMaker or Glue are often used by different teams or workloads, expected to operate within their own permissions and data silos. When a default role allows unrestricted access across services, it undermines this principle, enabling attackers to jump between services without detection.

The hypothetical attack path described by researchers is not just theoretical—machine learning workloads are increasingly integrated into business-critical pipelines, and third-party model repositories are commonly used. This introduces a new layer of risk from supply chain attacks, where malicious code hidden inside models can trigger a chain reaction of privilege escalation.

AWS’s response—tightening default role policies—is necessary but not sufficient. Security is a shared responsibility, and cloud users must continuously audit IAM roles, implement the principle of least privilege, and monitor role activity. Tools that automatically detect overly permissive roles and anomalous behaviors can help prevent these silent risks from escalating into breaches.

Moreover, the problem isn’t unique to AWS. The article’s reference to a privilege escalation flaw in Azure’s storage mounting utility reinforces a broader theme: cloud providers and third-party tools alike can introduce vulnerabilities that attackers will seek to exploit. Organizations adopting multi-cloud or hybrid environments must apply the same rigorous access management and threat monitoring across all platforms.

In essence, cloud security requires constant vigilance, automation, and a mindset that assumes default configurations are potential attack vectors. Ignoring this fact risks exposing sensitive data, compromising workloads, and eroding trust in cloud infrastructure.

Fact Checker Results ✅

The broad AmazonS3FullAccess policy in default IAM roles indeed poses a risk of lateral movement and privilege escalation within AWS environments.
AWS has officially modified these default role policies following the disclosure to reduce attack surface.
Similar privilege escalation issues exist in other cloud environments, such as the Azure mounting utility vulnerability addressed in January 2025.

Prediction 🔮

As cloud adoption accelerates, attackers will increasingly target default and misconfigured IAM roles as easy entry points. We predict growing demand for automated tools that continuously audit, visualize, and restrict IAM permissions to enforce least privilege. Additionally, supply chain risks linked to third-party repositories—like malicious machine learning models—will push organizations to adopt stronger validation and sandboxing mechanisms before importing external code into cloud services. Cloud providers themselves will likely evolve their default setups to be more secure out of the box, but ultimate protection will remain dependent on users’ proactive governance and security best practices.