CVE-2025-14503 identifies a critical privilege escalation vulnerability in the AWS Harmonix on AWS framework, specifically in versions 0.3.0 through 0.4.1. The root cause is an overly permissive IAM trust policy in the sample code for the EKS environment provisioning role, which is configured to trust the AWS account root principal. Because the root principal implicitly includes all IAM principals within the same AWS account, any user or service with sts:AssumeRole permissions can exploit this trust relationship to assume the provisioning role. This role typically has administrative privileges, enabling attackers to gain elevated permissions beyond their intended scope. The vulnerability does not require user interaction or external authentication, making it exploitable by any internal principal with minimal privileges. The CVSS 4.0 score is 8.6 (high), reflecting the network attack vector, low attack complexity, no required authentication, and high impact on confidentiality, integrity, and availability. AWS recommends upgrading to Harmonix on AWS v0.4.2 or later, where the trust policy has been corrected to restrict role assumption to intended principals only. No known exploits are reported in the wild yet, but the vulnerability poses a significant risk for privilege escalation within AWS accounts using the affected framework versions.

For European organizations, this vulnerability could lead to severe consequences including unauthorized administrative access to critical cloud infrastructure. Attackers or malicious insiders could leverage this flaw to escalate privileges, potentially leading to data breaches, disruption of services, or unauthorized changes to cloud resources. Given the widespread adoption of AWS and Kubernetes (EKS) in Europe, organizations using the Harmonix framework for EKS provisioning are at risk of lateral movement and full account compromise. This could impact confidentiality by exposing sensitive data, integrity by allowing unauthorized modifications, and availability by enabling destructive actions. The lack of required user interaction and the ability to exploit this vulnerability from within the same AWS account increases the threat level, especially in environments with multiple teams or third-party access. Regulatory compliance frameworks such as GDPR may also be impacted if data breaches occur due to this vulnerability.

European organizations should immediately upgrade any deployments of Harmonix on AWS from versions 0.3.0 through 0.4.1 to version 0.4.2 or later, where the IAM trust policy is properly restricted. Additionally, organizations should audit their IAM roles and trust policies to ensure that roles do not implicitly trust the root principal or overly broad principals. Implement the principle of least privilege by restricting sts:AssumeRole permissions only to specific, necessary IAM principals. Regularly review and monitor AWS CloudTrail logs for unusual AssumeRole activities, especially those involving administrative roles. Employ AWS IAM Access Analyzer to detect overly permissive trust policies. Consider segmenting AWS accounts or environments to limit the blast radius of any potential compromise. Finally, enforce strong internal controls and separation of duties to reduce the risk of insider threats exploiting this vulnerability.