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

Secrets can be retrieved from Vault using the Vault Agent sidecar container, which runs alongside your main application container. This sidecar can inject the secrets into your applications environment. One way to do this, is by means of rendering the secrets as a file. The file can then be picked up by your target application. However, in this case, the developer was unsure if the file was picked up, so instead of exporting the secret as an env-var, he echo-ed them.

Can you find the secret injected into application environment?

Answer to solution :

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.


0