# Ensure that the Containerd socket file ownership is set to root:root

- Source: https://support.icompaas.com/support/solutions/articles/62000234358-ensure-that-the-containerd-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 containerd.socket file, used for communication between Docker and containerd, should have its ownership set to root:root. This ensures that only authorized users (typically root) can modify or replace the socket file, preventing unauthorized access to containerd services.

**Rationale:**

The containerd.socket file is crucial for communication between Docker and containerd, and its security is important to prevent unauthorized access to containerd's internals. Allowing non-root users to own this file could lead to potential security breaches, such as unauthorized access to container management or manipulation of Docker’s container runtime.

**Impact:**

**Pros:**

-   Ensures that only root users can modify or access the socket file, enhancing security.
    
-   Prevents unauthorized users from tampering with the communication channel between Docker and containerd.
    

**Cons:**

-   Requires periodic checks to ensure that ownership is maintained correctly, especially after system updates or changes.
    

**Default Value:**

-   By default, the containerd.socket file should be owned by root:root. However, it could be altered by administrative errors or unauthorized access.
    

**Pre-requisites:**

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

**Remediation:**

**Test Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance running Docker.
    
2.  Verify the ownership of the containerd.socket file:  
    

**Using AWS CLI:**

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

**Implementation Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance.
    
2.  Set the ownership of the containerd.socket file to root:root:  
    
    sudo chown root:root /lib/systemd/system/containerd.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 modify the ownership of the containerd.socket file and restart Docker:  
    
    aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["sudo chown root:root /lib/systemd/system/containerd.socket && sudo systemctl daemon-reload && sudo systemctl restart docker"\]'
    

**Backout Plan:**

**Using AWS Console:**

1.  Log in to the EC2 instance.
    
2.  Revert the ownership of the containerd.socket file if necessary:  
    
    sudo chown <previous-owner>:<previous-group> /lib/systemd/system/containerd.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 and restart Docker:  
    
    aws ssm send-command --document-name "AWS-RunShellScript" --targets "Key=instanceIds,Values=instance\_id" --parameters 'commands=\["sudo chown <previous-owner>:<previous-group> /lib/systemd/system/containerd.socket && sudo systemctl daemon-reload && sudo systemctl restart docker"\]'
    

**References:**

-   [Docker Documentation - Docker Socket  
      
      
    ](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.