The Hidden Risk of Misconfigured ArgoCD on EC2 Instances

In modern cloud environments, speed and automation often take precedence over security. Tools like Kubernetes and GitOps platforms such as ArgoCD have become essential for managing complex deployments efficiently but even small misconfigurations in these systems can have far-reaching consequences.

This article is part of our Kubernetes Pentest Findings Series, where we share insights from a real-world security audit of a cloud-native environment. While the first post introduced the overall attack surface from Kubernetes to GitOps tools, this installment focuses on a specific vulnerability in ArgoCD running on AWS EC2. Here, we demonstrate how insecure configurations allowed us to extract sensitive instance metadata and AWS credentials, paving the way toward a potential full cloud compromise.

Why Misconfigured ArgoCD on AWS EC2 Poses a Serious Risk

ArgoCD enables GitOps-driven deployments. In AWS, clusters often run on EC2, where the Instance Metadata Service (IMDS) provides credentials and metadata to workloads. IMDSv1 is insecure by default, while IMDSv2 improves protection by requiring session tokens. Small oversights at each layer add up to full cloud compromise.

Exploiting ArgoCD to Access AWS Instance Metadata Service (IMDS)

We discovered that ArgoCD could be tricked into fetching external URLs during app creation. By supplying the IMDS endpoint (169.254.169.254), ArgoCD fetched sensitive metadata and displayed it in its UI.

http://169.254.169.254/latest/dynamic/instance-identity/document

Next, we targeted credential endpoints. ArgoCD fetched IAM credentials directly from IMDS, exposing AWS keys with valid permissions.

With those credentials, we enumerated privileges using tools like enumerate-iam. Depending on the role’s permissions, attackers could:

• Spin up or delete EC2 instances.
• Access S3 buckets.
• Modify IAM roles.

How Attackers Can Steal AWS Credentials and Escalate Privileges

Exploiting this weakness allowed us to pivot from Kubernetes into the underlying AWS infrastructure. By abusing ArgoCD’s ability to fetch external resources, an attacker could interact with the Instance Metadata Service (IMDS) and retrieve sensitive data. This has several severe consequences:

• Environment Mapping: Access to instance identity documents provides detailed metadata, enabling attackers to map out the AWS account and its resources.
• Credential Theft: Temporary IAM credentials can be extracted directly from IMDS, giving attackers cloud access under the instance’s role.
• Privilege Escalation: With valid AWS keys, adversaries can enumerate and potentially escalate privileges. Depending on the IAM role’s permissions, this may allow spinning up or terminating instances, accessing S3 data, or modifying IAM roles.
• Cloud Compromise: In the worst case, this chain of weaknesses could lead to full control over critical cloud resources, persistence in the environment, and disruption of business operations.

Securing ArgoCD, IMDS, and IAM Roles Against Exploitation

Mitigating this issue requires a combination of infrastructure hardening, configuration reviews, and principle-of-least-privilege enforcement:

• Restrict Egress Access from ArgoCD: Prevent ArgoCD from reaching IMDS and other sensitive internal endpoints by applying strict network egress policies.
• Enforce IMDSv2: Require token-based access to the Instance Metadata Service, which blocks trivial metadata harvesting.
• Harden IAM Roles – Ensure that instance profiles and roles follow the principle of least privilege. Limit permissions to only what ArgoCD requires, and avoid assigning broad or administrative rights.
• Audit ArgoCD Configurations: Regularly review repository and application definitions to catch unintended URL proxying or external fetches. Security guardrails should be implemented to detect misconfigurations early.

Lessons from ArgoCD Misconfigurations

This pentest finding highlights how small misconfigurations in a widely used tool like ArgoCD can open the door to disproportionate risks. By chaining together seemingly minor oversights, attackers could move from Kubernetes into AWS infrastructure, harvesting credentials and potentially achieving full cloud compromise. The lesson is clear: security in cloud-native environments about carefully managing configurations, access controls, and trust boundaries.

In the next part of our series, we’ll dive into another real-world scenario: how a GoCD Agent RCE led to GitHub token leakage, exposing critical source code assets. Stay tuned to see how this weakness unfolded and what organizations can do to prevent similar risks.