Challenge 46 ☆☆☆☆

Welcome to challenge Challenge 46. You need to guess the secret that is hidden in Java, Docker, Kubernetes, Vault, AWS or GCP.

HashiCorp Vault Template Injection

Vault template injection via agent injection typically involves injecting a sidecar container, known as the Vault Agent, alongside your main application container. The Vault Agent is responsible for interacting with HashiCorp Vault to retrieve secrets and inject them into the application’s runtime environment.

Can you find secret injected into application environment?

Answer to solution :

This challenge can be solved using the following steps:

  1. Run kubectl get pods -A and find secret-challenge-xxx pod name

  2. Run kubectl exec secret-challenge-xxx -c secret-challenge -n default — cat vault/secrets/challenge46 where xxx is the rest of the randomly generated pod name. to print injected secrets from vault.

Note: if you are running this on a hosted environment, where you do not have access to the Kubernetes cluster, ask the organizer of the hosted solution to execute the commands for you and return the results.

Why Vault Template Injection is not always a good idea?

While Vault agent injection via templates can be a convenient way to manage secrets in certain scenarios, there are situations where it might not be the best approach.

Templates might accidentally expose sensitive information in logs or temporary files. If not properly configured, secrets could end up in places where they are accessible by unauthorized users or processes.

Let’s consider an example involving a template injection attack in a scripted language like PHP:

  1. Imagine a scenario where PHP application uses a template with sensitive information

    • where template can look like this: $password = "'; system('rm -rf /'); //"

  2. When the template is processed it can become:

    • $connection = "password='; system('rm -rf /'); //"

To prevent such issues its crucial to ensure that the values retrieved from Vault are properly validated.