Cis AWS Compute 3.4

Ensure Amazon ECS task definitions do not have 'privileged' set to 'true'

Description

Ensure that Amazon ECS task definitions do not grant privileged access to the host container instance.

Note: This recommendation assumes that only the latest active revision of a task definition is in use. If older revisions are in use, apply the audit and remediation procedures to those revisions as needed.

Rationale

Restricting privileged access enhances security of the host container instance by maintaining isolation and reducing the risk of privilege escalation.

Impact

There may be some administrative effort required to ensure Amazon ECS applications function as expected without privileged access.

Audit Procedure

Using AWS Console

1. Login to the ECS console using https://console.aws.amazon.com/ecs/.
2. In the left panel, click Task definitions.
3. Click the name of a task definition.
4. Click on the latest active revision of the task definition.
5. Click JSON.
6. For each element under containerDefinitions, ensure that privileged is set to false or is absent.
7. Repeat steps 1-6 for each task definition.

Using AWS CLI

Run the following command to list task definitions:

aws ecs list-task-definitions

For the latest revision of a task definition, run the following command:

aws ecs describe-task-definition --task-definition <task-definition-arn> --query 'taskDefinition.containerDefinitions[*].privileged'

Ensure that the command does not return true. Repeat for each task definition.

Expected Result

The privileged parameter should be false or absent for all containers in all task definitions.

Remediation

Using AWS Console

1. Login to the ECS console using https://console.aws.amazon.com/ecs/.
2. In the left panel, click Task definitions.
3. Click the name of a task definition.
4. Click on the latest active revision of the task definition.
5. Click Create new revision.
6. Click Create new revision with JSON.
7. For each element under containerDefinitions, set privileged to false, or remove "privileged": true.
8. Click Create.
9. Repeat steps 1-8 for each task definition requiring remediation.

Note: When a task definition is updated, running tasks launched from the previous task definition remain unchanged. Updating a running task requires redeploying it with the new task definition.

Using AWS CLI

No specific CLI remediation provided. Register a new task definition revision with corrected privileged setting using aws ecs register-task-definition.

Default Value

By default, privileged is set to false.

References

1. https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html
2. https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ecs/list-task-definitions.html
3. https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ecs/describe-task-definition.html

CIS Controls

Profile

Level 1 | Automated