Minimize container added capabilities

ID: minimize-added-capabilities

Severity: high

Author: princechaddha

Tags: cloud,devops,kubernetes,k8s,devsecops,deployments,k8s-cluster-security

Description

Checks for containers in Kubernetes Deployments with added capabilities beyond the default set, increasing security risks.

YAML Source

id: minimize-added-capabilities

info:
  name: Minimize container added capabilities
  author: princechaddha
  severity: high
  description: Checks for containers in Kubernetes Deployments with added capabilities beyond the default set, increasing security risks.
  impact: |
    Containers with additional capabilities are granted more privileges than necessary, potentially allowing them to bypass intended security restrictions. This increases the risk of exploitation and unauthorized access.
  remediation: |
    Ensure that no unnecessary capabilities are added to containers within Kubernetes Deployments. Use security contexts to define the minimum necessary privileges.
  reference:
    - https://kubernetes.io/docs/tasks/configure-pod-container/security-context/
  tags: cloud,devops,kubernetes,k8s,devsecops,deployments,k8s-cluster-security

flow: |
  code(1);
  for (let deployment of template.items) {
    set("deployment", deployment)
    javascript(1);
  }

self-contained: true
code:
  - engine:
      - sh
      - bash
    source: kubectl get deployments --all-namespaces --output=json
    extractors:
      - type: json
        name: items
        internal: true
        json:
          - '.items[]'

javascript:
  - code: |
        deployment = JSON.parse(template.deployment);
        for (const container of deployment.spec.template.spec.containers) {
          if (container.securityContext && container.securityContext.capabilities && container.securityContext.capabilities.add && container.securityContext.capabilities.add.length > 0) {
            let addedCaps = container.securityContext.capabilities.add.join(', ');
            let result = (`Deployment '${deployment.metadata.name}' in namespace '${deployment.metadata.namespace}' has added capabilities: ${addedCaps}.`);
            Export(result);
          }
        }

    extractors:
      - type: dsl
        dsl:
          - response
# digest: 4a0a004730450220124114af021a11a80719774956bdf248b9fe97cbdd61e61433f28a48ee96a92f022100a5e1f40ae680a3d7ea7f2933bbb23962fbc28fe442ddcae9688f6c6137e31dc8:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

$ nuclei -u "URL" -t "cloud/kubernetes/deployments/k8s-minimize-added-capabilities.yaml"

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