# Ensure that docker.socket file ownership is set to root:root

- Source: https://support.icompaas.com/support/solutions/articles/62000234332-ensure-that-docker-socket-file-ownership-is-set-to-root-root
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [CIS Docker Benchmark v1.7.0](https://support.icompaas.com/support/solutions/62000112687) › [CIS Docker Benchmark](https://support.icompaas.com/support/solutions/folders/62000169241)
- Last updated: 2026-05-29
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**Profile Applicability:**

-   **Level 1**
    

**Description:**

The docker.socket file, typically located in /lib/systemd/system/docker.socket, is responsible for the communication between the Docker client and Docker daemon. It is important to ensure that this file is owned by root:root to prevent unauthorized modifications or access.

**Rationale:**

The docker.socket file is a critical part of Docker's configuration and controls access to the Docker daemon. Allowing non-root users to own or modify this file can lead to security vulnerabilities, such as unauthorized access to the Docker API or tampering with the Docker service.

**Impact:**

**Pros:**

-   Ensures that only the root user has control over Docker’s communication socket.
    
-   Reduces the risk of unauthorized users or processes tampering with Docker's internal communication mechanisms.
    

**Cons:**

-   Requires periodic checks to ensure that ownership is not inadvertently changed.
    

**Default Value:**

By default, the docker.socket file is typically owned by root:root, but ownership can be modified by administrative errors or unauthorized access.

**Pre-requisites:**

-   Administrative privileges on the Docker host system.
    
-   Access to the file system to inspect and modify file ownership.
    

**Remediation**

**Test Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance running Docker.
    
2.  Verify the ownership of the docker.socket file:
    
    ls -l /lib/systemd/system/docker.socket
    

**Using AWS CLI:**

1.  Connect to the EC2 instance where Docker is running.
    
2.  Run the following command to verify the ownership of the docker.socket file:  
    
    ls -l /lib/systemd/system/docker.socket
    

**Implementation Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance.
    
2.  Set the ownership of the docker.socket file to root:root:  
    
    sudo chown root:root /lib/systemd/system/docker.socket
    
3.  Reload the systemd daemon to apply any changes:  
    
    sudo systemctl daemon-reload
    
4.  Restart Docker to ensure the changes take effect:  
    
    sudo systemctl restart docker
    

**Using AWS CLI:**

1.  Use SSM to change the ownership of the docker.socket file and restart Docker:
    
    aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["sudo chown root:root /lib/systemd/system/docker.socket && sudo systemctl daemon-reload && sudo systemctl restart docker"\]'
    

**Backout Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance.
    
2.  Revert the ownership of the docker.socket file if necessary:  
    
    sudo chown <previous-owner>:<previous-group> /lib/systemd/system/docker.socket
    
      
    
3.  Reload systemd and restart Docker:  
    
    sudo systemctl daemon-reload
    sudo systemctl restart docker
    

**Using AWS CLI:**

1.  Use SSM to revert the ownership of the docker.socket file:  
    
    aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["sudo chown <previous-owner>:<previous-group> /lib/systemd/system/docker.socket && sudo systemctl daemon-reload && sudo systemctl restart docker"\]'
    

**References:**

-   [Docker Daemon Socket Option](https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-socket-option)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.