---
title: ECS task definition network mode not recommended
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > ECS task definition network mode not
  recommended
---

# ECS task definition network mode not recommended

{% callout %}
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{% alert level="danger" %}
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{% /callout %}

## Metadata{% #metadata %}

**Id:** `cloudformation-aws-ecs-task-definition-network-mode-not-recommended` 

**Provider:** AWS

**Platform:** CloudFormation

**Severity:** Medium

**Category:** Insecure Configurations

#### Learn More{% #learn-more %}

- [Provider Reference](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-taskdefinition.html#cfn-ecs-taskdefinition-networkmode)

### Description{% #description %}

Amazon ECS task definitions should use `NetworkMode` set to `awsvpc` so each task receives its own elastic network interface and can be protected by VPC security groups. This enables per-task network isolation and reduces the blast radius of compromised containers.

In CloudFormation, the `AWS::ECS::TaskDefinition` resource's `NetworkMode` property must be defined and set to `awsvpc`. If `NetworkMode` is undefined, it defaults to `bridge`. Resources missing the property or with any other value (for example, `bridge` or `host`) will be flagged because they cannot leverage task-level security groups.

Secure configuration example:

```yaml
MyTaskDefinition:
  Type: AWS::ECS::TaskDefinition
  Properties:
    Family: my-task
    NetworkMode: awsvpc
    ContainerDefinitions:
      - Name: my-container
        Image: nginx:latest
        Essential: true
```

## Compliant Code Examples{% #compliant-code-examples %}

```yaml
AWSTemplateFormatVersion: "2010-09-09"
Description: A sample template
Resources:
  taskdefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      NetworkMode: awsvpc
      ContainerDefinitions:
        - Name:
            Ref: "AppName"
          MountPoints:
            - SourceVolume: "my-vol"
              ContainerPath: "/var/www/my-vol"
          Image: "amazon/amazon-ecs-sample"
          Cpu: 256
          PortMappings:
            - ContainerPort:
                Ref: "AppContainerPort"
              HostPort:
                Ref: "AppHostPort"
          EntryPoint:
            - "/usr/sbin/apache2"
            - "-D"
            - "FOREGROUND"
          HealthCheck:
            Command:
              - CMD-SHELL
              - curl -f http://localhost:8080/ || exit 1
            Interval: 30
            Retries: 3
            StartPeriod: 1
            Timeout: 5
          Memory: 512
          Essential: true
```

```json
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": "A sample template",
  "Resources": {
    "taskdefinition": {
      "Type": "AWS::ECS::TaskDefinition",
      "Properties": {
        "Volumes": [
          {
            "Host": {
              "SourcePath": "/var/lib/docker/vfs/dir/"
            },
            "Name": "my-vol"
          }
        ],
        "NetworkMode": "awsvpc",
        "ContainerDefinitions": [
          {
            "EntryPoint": [
              "/usr/sbin/apache2",
              "-D",
              "FOREGROUND"
            ],
            "Memory": 512,
            "PortMappings": [
              {
                "ContainerPort": {
                  "Ref": "AppContainerPort"
                },
                "HostPort": {
                  "Ref": "AppHostPort"
                }
              }
            ],
            "MountPoints": [
              {
                "SourceVolume": "my-vol",
                "ContainerPath": "/var/www/my-vol"
              }
            ],
            "Image": "amazon/amazon-ecs-sample",
            "Cpu": 256,
            "HealthCheck": {
              "Command": [
                "CMD-SHELL",
                "curl -f http://localhost:8080/ || exit 1"
              ],
              "Interval": 30,
              "Retries": 3,
              "StartPeriod": 1,
              "Timeout": 5
            },
            "Essential": true,
            "Name": {
              "Ref": "AppName"
            }
          }
        ]
      }
    }
  }
}
```

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```yaml
AWSTemplateFormatVersion: "2010-09-09"
Description: A sample template
Resources:
  taskdefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      NetworkMode: none
      ContainerDefinitions:
        - Name:
            Ref: "AppName"
          MountPoints:
            - SourceVolume: "my-vol"
              ContainerPath: "/var/www/my-vol"
          Image: "amazon/amazon-ecs-sample"
          Cpu: 256
          PortMappings:
            - ContainerPort:
                Ref: "AppContainerPort"
              HostPort:
                Ref: "AppHostPort"
          EntryPoint:
            - "/usr/sbin/apache2"
            - "-D"
            - "FOREGROUND"
          Memory: 512
          Essential: true
```

```json
{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Description": "A sample template",
  "Resources": {
    "taskdefinition": {
      "Type": "AWS::ECS::TaskDefinition",
      "Properties": {
        "ContainerDefinitions": [
          {
            "MountPoints": [
              {
                "SourceVolume": "my-vol",
                "ContainerPath": "/var/www/my-vol"
              }
            ],
            "Image": "amazon/amazon-ecs-sample",
            "Cpu": 256,
            "PortMappings": [
              {
                "HostPort": {
                  "Ref": "AppHostPort"
                },
                "ContainerPort": {
                  "Ref": "AppContainerPort"
                }
              }
            ],
            "EntryPoint": [
              "/usr/sbin/apache2",
              "-D",
              "FOREGROUND"
            ],
            "Memory": 512,
            "Essential": true,
            "Name": {
              "Ref": "AppName"
            }
          }
        ],
        "Volumes": [
          {
            "Host": {
              "SourcePath": "/var/lib/docker/vfs/dir/"
            },
            "Name": "my-vol"
          }
        ]
      }
    }
  }
}
```