CVE-2025-14503: Amazon Harmonix Privilege Escalation Flaw

CVE-2025-14503 Overview

CVE-2025-14503 is a privilege escalation vulnerability in the Harmonix on AWS framework. The sample code for the Amazon Elastic Kubernetes Service (EKS) environment provisioning role contains an overly-permissive Identity and Access Management (IAM) trust policy. The role trusts the AWS account root principal, which allows any IAM principal in the same AWS account with sts:AssumeRole permissions to assume the role and gain administrative privileges. The flaw affects Harmonix on AWS versions v0.3.0 through v0.4.1. AWS published advisory AWS-2025-031 and released a fix in version v0.4.2.

Critical Impact

Any low-privileged IAM principal in the same AWS account can assume the EKS provisioning role and obtain administrative privileges within the Harmonix-deployed environment.

Affected Products

• Amazon Harmonix on AWS v0.3.0
• Amazon Harmonix on AWS versions through v0.4.1
• Harmonix EKS environment provisioning role sample code

Discovery Timeline

• 2025-12-15 - CVE-2025-14503 published to NVD
• 2026-01-30 - Last updated in NVD database

Technical Details for CVE-2025-14503

Vulnerability Analysis

The vulnerability is classified as Incorrect Privilege Assignment [CWE-266]. Harmonix on AWS is an internal developer platform framework that provisions cloud infrastructure, including EKS environments. The framework includes sample IAM role configurations used to provision and manage EKS clusters. These provisioning roles hold administrative privileges over the cluster lifecycle. The flaw stems from how the trust policy on the EKS provisioning role is written, not from a defect in IAM itself.

Root Cause

The EKS environment provisioning role's trust policy uses the AWS account root principal (arn:aws:iam::<account-id>:root) as a trusted entity. In AWS IAM, naming the account root as a trusted principal delegates trust evaluation to identity-based policies within that account. Any IAM principal in the same account that has sts:AssumeRole for the role's Amazon Resource Name (ARN), even through a broad wildcard policy, can assume the role. The sample code did not scope the trust policy to a specific deployment role or federated identity.

Attack Vector

An attacker requires existing access to an IAM principal within the same AWS account. The principal must hold sts:AssumeRole permissions covering the Harmonix EKS provisioning role. The attacker calls sts:AssumeRole against the role ARN, receives temporary administrative credentials, and uses them to manipulate the EKS environment. This includes deploying workloads, modifying cluster configuration, and accessing data the provisioning role controls. No network exploit, user interaction, or external code execution is required.

No public proof-of-concept exploit is available. Refer to the GitHub Security Advisory GHSA-qm86-gqrq-mqcw and the Harmonix Pull Request 189 for the corrected trust policy.

Detection Methods for CVE-2025-14503

Indicators of Compromise

• CloudTrail AssumeRole events targeting the Harmonix EKS provisioning role from IAM principals that are not part of the documented deployment workflow.
• Unexpected sts:GetCallerIdentity calls followed by EKS control-plane API actions originating from the assumed role's session.
• New EKS workloads, node groups, or RBAC bindings created by sessions tied to the provisioning role outside of change windows.

Detection Strategies

• Audit IAM trust policies across the account for any role trusting root and cross-reference with Harmonix deployments at versions v0.3.0 through v0.4.1.
• Use IAM Access Analyzer to identify roles assumable by unintended principals within the account.
• Review CloudTrail for AssumeRole API calls whose userIdentity.arn does not match the approved deployment automation identity.

Monitoring Recommendations

• Forward CloudTrail management events to a centralized log store and alert on AssumeRole against Harmonix role ARNs.
• Monitor EKS audit logs for high-privilege actions executed by the provisioning role outside scheduled provisioning windows.
• Track changes to IAM role trust policies through AWS Config rules such as iam-role-managed-policy-check.

How to Mitigate CVE-2025-14503

Immediate Actions Required

• Upgrade Harmonix on AWS to version v0.4.2 or later if running any version between v0.3.0 and v0.4.1.
• Update the EKS environment provisioning role trust policy to restrict the Principal to the specific deployment role or federated identity used by Harmonix automation.
• Review CloudTrail history for prior AssumeRole calls against the affected role and investigate any unexpected sessions.

Patch Information

AWS released Harmonix on AWS v0.4.2, which replaces the overly-permissive trust policy in the sample EKS provisioning role. The corrected configuration is published in Harmonix Pull Request 189. See the AWS Security Bulletin AWS-2025-031 for vendor guidance.

Workarounds

• Manually edit the EKS provisioning role trust policy to remove the account root principal and specify only the intended deployment principal ARN.
• Apply an IAM permissions boundary or Service Control Policy (SCP) that denies sts:AssumeRole against the Harmonix role for all principals except the approved automation identity.
• Restrict sts:AssumeRole in account-wide IAM policies so that broad wildcards do not cover the affected role ARN.

# Example: scope the Harmonix EKS provisioning role trust policy to a specific deployment role
# Replace <account-id> and <deployment-role-name> with environment-specific values
aws iam update-assume-role-policy \
  --role-name harmonix-eks-provisioning-role \
  --policy-document '{
    "Version": "2012-10-17",
    "Statement": [
      {
        "Effect": "Allow",
        "Principal": {
          "AWS": "arn:aws:iam::<account-id>:role/<deployment-role-name>"
        },
        "Action": "sts:AssumeRole"
      }
    ]
  }'