This vulnerability occurs when an IAM user updates the AssumeRolePolicyDocument of an IAM role they can assume, granting themselves access to additional permissions. By modifying the policy, the IAM user can escalate their privileges and gain access to resources they are not authorized to access. Additionally, the attacker can use the sts:AssumeRole API to assume the IAM role they modified and access the resources that the role has permissions to. This privilege escalation attack can lead to unauthorized access to sensitive data, unauthorized modifications of resources, and potential service disruptions.
To remediate an IAM user's ability to execute a privilege escalation by using UpdateAssumeRolePolicy and sts:AssumeRole, you can follow these steps:
- Review and identify the specific IAM user or users that have the permissions to execute this privilege escalation.
- Remove the UpdateAssumeRolePolicy permission from the affected IAM user(s).
- Restrict the sts:AssumeRole permission to only the specific roles that the IAM user needs to assume.
- Implement the principle of least privilege by granting only the necessary permissions to the IAM user.
- Monitor the IAM user's activity and regularly review the IAM policies to ensure they align with the organization's security requirements.
It is also important to regularly review the IAM users and their permissions to ensure they align with the organization's security requirements.
Note: Remediation steps provided by Lightlytics are meant to be suggestions and guidelines only. It is crucial to thoroughly verify and test any remediation steps before applying them to production environments. Each organization's infrastructure and security needs may differ, and blindly applying suggested remediation steps without proper testing could potentially cause unforeseen issues or vulnerabilities. Therefore, it is strongly recommended that you validate and customize any remediation steps to meet your organization's specific requirements and ensure that they align with your security policies and best practices.