Critical Vulnerability in AWS Default IAM Roles Exposes Cloud Environments to Attacks

A recent discovery by Aqua Security's Team Nautilus has unveiled a significant vulnerability in Amazon Web Services (AWS) that could allow malicious actors to exploit default Identity and Access Management (IAM) roles. This flaw, termed the "Shadow Role" vulnerability, poses a serious risk to organizations utilizing various AWS services, potentially leading to privilege escalation and full account compromise.

Key Takeaways

• Vulnerability Found: Default IAM roles in AWS services can be exploited for lateral movement and privilege escalation.

• Affected Services: The flaw impacts services like Glue, SageMaker, EMR, CloudFormation, Redshift, and CodeBuild.

• Attack Vector: Attackers can predict role names and create malicious resources to gain unauthorized access.

• AWS Response: AWS has updated its policies to mitigate the risk, but organizations are advised to audit their IAM roles.

Understanding The Vulnerability

The vulnerability arises from AWS's practice of automatically creating default IAM roles when certain services are utilized in new regions. These roles, designed to facilitate service operations, often come with overly permissive trust policies that can be exploited without user interaction.

Researchers found that if an attacker can predict the naming convention of these roles, they can create a resource in another AWS account with the same name. When the victim triggers the vulnerable service, AWS may trust the malicious resource due to the pre-set trust policy, allowing the attacker to assume the role and gain elevated privileges.

Implications of The Flaw

The implications of this vulnerability are profound, particularly for organizations with sensitive workloads. Here are some key points regarding the potential impact:

• Lateral Movement: Attackers can move across services within the same AWS account, leveraging the compromised IAM role to access other resources.

• Privilege Escalation: With roles like AmazonS3FullAccess, attackers can manipulate S3 buckets and other AWS services, effectively gaining control over the entire environment.

• Automated Role Creation: Many of these roles are created automatically, often without the knowledge of administrators, making them difficult to monitor and secure.

Specific Services Affected

The following AWS services have been identified as having vulnerable default IAM roles:

• Amazon SageMaker: Creates a role with full S3 access when setting up a domain.

• AWS Glue: Generates a service role that also includes full S3 access.

• Amazon EMR: Assigns a role with broad permissions, allowing extensive access to S3 buckets.

Recommended Actions for Organizations

In light of these findings, organizations are urged to take proactive measures to secure their AWS environments:

1. Audit IAM Roles: Regularly review and audit IAM roles, especially those created automatically, to identify and mitigate risks.

2. Implement Tighter Controls: Ensure that trust policies are strictly limited to necessary resources and actions.

3. Monitor Activity: Utilize tools and detection queries to monitor for suspicious activity related to IAM roles.

The discovery of the Shadow Role vulnerability highlights the complexities and risks associated with identity and access management in cloud environments. While AWS has taken steps to address the issue, organizations must remain vigilant and proactive in securing their cloud infrastructures against potential threats. This incident serves as a reminder of the importance of understanding default configurations and the need for continuous monitoring and auditing in cloud security practices.

As cyber threats become increasingly sophisticated, your security strategy must evolve to keep pace. BetterWorld Technology offers adaptive cybersecurity solutions that grow with the threat landscape, helping your business stay secure while continuing to innovate. Reach out today to schedule your personalized consultation.

Sources

• “Shadow Role” Vulnerability In AWS Services Could Lead To Full Account Takeover, Information Security Buzz.

• AWS Default IAM Roles Found to Enable Lateral Movement and Cross-Service Exploitation, The Hacker News.