Service Account Token Automount Not Disabled

• Query id: a9a13d4f-f17a-491b-b074-f54bffffcb4a
• Query name: Service Account Token Automount Not Disabled
• Platform: Terraform
• Severity: Medium
• Category: Insecure Defaults
• CWE: 665
• URL: Github

Description

Service Account Tokens are automatically mounted even if not necessary
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "kubernetes_deployment" "example" {
  metadata {
    name = "terraform-example"
    labels = {
      test = "MyExampleApp"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        test = "MyExampleApp"
      }
    }

    template {
      metadata {
        labels = {
          test = "MyExampleApp"
        }
      }

      spec {
        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}


resource "kubernetes_daemonset" "example2" {
  metadata {
    name      = "terraform-example"
    namespace = "something"
    labels = {
      test = "MyExampleApp"
    }
  }

  spec {

    selector {
      match_labels = {
        test = "MyExampleApp"
      }
    }

    template {
      metadata {
        labels = {
          test = "MyExampleApp"
        }
      }

      spec {

        automount_service_account_token = true

        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }

        }
      }
    }
  }
}

resource "kubernetes_cron_job" "demo3" {
  metadata {
    name = "demo"
  }
  spec {
    concurrency_policy            = "Replace"
    failed_jobs_history_limit     = 5
    schedule                      = "1 0 * * *"
    starting_deadline_seconds     = 10
    successful_jobs_history_limit = 10
    job_template {
      metadata {}
      spec {
        backoff_limit              = 2
        ttl_seconds_after_finished = 10
        template {
          metadata {}
          spec {
            automount_service_account_token = true
            container {
              name    = "hello"
              image   = "busybox"
              command = ["/bin/sh", "-c", "date; echo Hello from the Kubernetes cluster"]
            }
          }
        }
      }
    }
  }
}

resource "kubernetes_pod" "test6" {
  metadata {
    name = "terraform-example"
  }

  spec {
    container {
      image = "nginx:1.7.9"
      name  = "example"

      env {
        name  = "environment"
        value = "test"
      }

      port {
        container_port = 8080
      }

      liveness_probe {
        http_get {
          path = "/nginx_status"
          port = 80

          http_header {
            name  = "X-Custom-Header"
            value = "Awesome"
          }
        }

        initial_delay_seconds = 3
        period_seconds        = 3
      }
    }

    dns_config {
      nameservers = ["1.1.1.1", "8.8.8.8", "9.9.9.9"]
      searches    = ["example.com"]

      option {
        name  = "ndots"
        value = 1
      }

      option {
        name = "use-vc"
      }
    }

    dns_policy = "None"
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "kubernetes_deployment" "example9" {
  metadata {
    name = "terraform-example"
    labels = {
      test = "MyExampleApp"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        test = "MyExampleApp"
      }
    }

    template {
      metadata {
        labels = {
          test = "MyExampleApp"
        }
      }

      spec {
        automount_service_account_token = false
        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}


resource "kubernetes_daemonset" "example22" {
  metadata {
    name      = "terraform-example"
    namespace = "something"
    labels = {
      test = "MyExampleApp"
    }
  }

  spec {

    selector {
      match_labels = {
        test = "MyExampleApp"
      }
    }

    template {
      metadata {
        labels = {
          test = "MyExampleApp"
        }
      }

      spec {

        automount_service_account_token = false

        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }

        }
      }
    }
  }
}

resource "kubernetes_cron_job" "demo32" {
  metadata {
    name = "demo"
  }
  spec {
    concurrency_policy            = "Replace"
    failed_jobs_history_limit     = 5
    schedule                      = "1 0 * * *"
    starting_deadline_seconds     = 10
    successful_jobs_history_limit = 10
    job_template {
      metadata {}
      spec {
        backoff_limit              = 2
        ttl_seconds_after_finished = 10
        template {
          metadata {}
          spec {
            automount_service_account_token = false
            container {
              name    = "hello"
              image   = "busybox"
              command = ["/bin/sh", "-c", "date; echo Hello from the Kubernetes cluster"]
            }
          }
        }
      }
    }
  }
}

resource "kubernetes_pod" "test62" {
  metadata {
    name = "terraform-example"
  }

  spec {
    automount_service_account_token = false
    container {
      image = "nginx:1.7.9"
      name  = "example"

      env {
        name  = "environment"
        value = "test"
      }

      port {
        container_port = 8080
      }

      liveness_probe {
        http_get {
          path = "/nginx_status"
          port = 80

          http_header {
            name  = "X-Custom-Header"
            value = "Awesome"
          }
        }

        initial_delay_seconds = 3
        period_seconds        = 3
      }
    }

    dns_config {
      nameservers = ["1.1.1.1", "8.8.8.8", "9.9.9.9"]
      searches    = ["example.com"]

      option {
        name  = "ndots"
        value = 1
      }

      option {
        name = "use-vc"
      }
    }

    dns_policy = "None"
  }
}