Write below root
Event Information
Meaning
- The “Write below root” event in a Kubernetes cluster indicates that a process running within a container attempted to write or modify files or directories that are located below the root directory (”/”) of the file system.
- This event can be a potential security concern as it may indicate unauthorized access or tampering with critical system files or directories.
- To investigate and mitigate this event, you can:
- Identify the specific container and pod where the event occurred using the Kubernetes cluster’s monitoring or logging tools.
- Inspect the process or application running within the container to determine the intent behind the write operation and whether it was legitimate or malicious.
- Review the container’s security policies and configurations to ensure that only authorized processes have write access to system files and directories below the root level.
Remediation
- Create a Python script that uses the Kubernetes Python client library to interact with the Kubernetes API.
- Use the script to create a Kubernetes manifest file in the correct format to deploy a Pod with a Python container.
- In the manifest file, include a volume mount to mount the root filesystem of the host machine to the Pod.
- Inside the Python container, write a script that uses the
os
module to open and write to the file below the root directory. - Build a Docker image with the Python script and push it to a container registry.
- Update the Kubernetes manifest file to use the newly built Docker image.
- Use the
kubectl apply
command to deploy the updated manifest file and remediate the event.
Note: It is important to consider the security implications of allowing a container to write below the root directory. Ensure that this remediation script is compliant with your organization’s security and compliance standards.