Read environment variable from proc files

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Event Information

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Meaning

• The “Read environment variable from proc files” event in a Kubernetes cluster indicates that a process running within a container is attempting to read environment variables from the /proc filesystem.
• This event could potentially indicate a security concern, as reading environment variables from /proc can expose sensitive information such as passwords or API keys.
• To investigate this event, you can use the kubectl command to check the logs of the container where the event occurred. For example, you can use “kubectl logs <pod_name> -c <container_name>” to view the logs and look for any suspicious activity related to reading environment variables from /proc.

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Remediation

1. Isolate Environment Variables Using ConfigMaps:

   • Instead of allowing environment variables to be read from /proc, it is more secure to manage and inject environment variables using ConfigMaps or Secrets in Kubernetes.
   • Create ConfigMap

   apiVersion: v1
   kind: ConfigMap
   metadata:
    name: env-vars
   data:
    MY_ENV_VAR: "<value>"  
   
   - Apply the ConfigMap:
   ```kubectl apply -f configmap.yaml``` 
   
   

2. Use Secrets for Sensitive Data:

   • If the environment variable contains sensitive information (like API keys or passwords), use a Secret instead of a ConfigMap:

   apiVersion: v1
   kind: Secret
   metadata:
    name: sensitive-env-vars
   type: Opaque
   data:
    MY_SECRET_VAR: <base64-encoded-value>
   

   • Apply the Secret: kubectl apply -f secret.yaml

3. Mount the ConfigMap or Secret to the Pod:

   • Modify the deployment manifest to reference the ConfigMap or Secret for injecting environment variables securely:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
    name: my-deployment
   spec:
     template:
       spec:
         containers:
          - name: my-container
            image: my-image
            envFrom:
              - configMapRef:
                  name: env-vars
              - secretRef:
                  name: sensitive-env-vars
   
   

4. Restrict Access to the /proc Filesystem:

   • Prevent processes from unnecessarily accessing the /proc filesystem by limiting the permissions of the container.
   • Ensure that the container is not running in privileged mode, which could allow it to access sensitive areas of the host system, including /proc. Modify the container’s security context to explicitly disable privileged access:

   securityContext:
     privileged: false
     readOnlyRootFilesystem: true