Jupyter Enterprise Gateway Kubernetes Manifest Injection Vulnerability

A YAML injection vulnerability has been identified in Jupyter Enterprise Gateway versions prior to 3.3.0. The issue arises because the server interpolates untrusted environment variables into Kubernetes manifests without proper YAML-aware escaping. This flaw allows attackers to inject new fields, overwrite existing critical fields, and manipulate document boundaries to create multiple Kubernetes resources. Exploitation could lead to the creation of arbitrary resources, such as privileged pods.

Impact

Exploitation of this vulnerability allows for the injection of malicious YAML into Kubernetes manifests, which can overwrite existing fields and inject new resources. This could lead to the creation of privileged pods, potentially compromising the underlying host or Kubernetes cluster.

Reproduction

To reproduce this vulnerability, send a POST request to the '/api/kernels' endpoint with injected data in the 'KERNEL_WORKING_DIR' environment variable. The injected data can include YAML that overwrites existing Kubernetes pod security settings or injects new resources altogether.

Remediation

Users can upgrade to Jupyter Enterprise Gateway version 3.3.0 or later, where this vulnerability has been fixed.