Container Runtime Security

Beyond image security, runtime protection monitors and secures running containers. Kubernetes environments require specific security attention.

Kubernetes Security

RBAC configuration - Role-Based Access Control defines who can do what in the cluster. Implement least privilege.

Network policies - Control pod-to-pod communication. Default deny with explicit allows.

Pod security standards - Enforce security contexts: non-root users, read-only filesystems, capability restrictions.

API server security - Secure the Kubernetes API. Authentication, authorization, audit logging.

Secrets management - Use Kubernetes secrets or external vault systems. Encrypt secrets at rest.

Node security - Harden underlying hosts. Keep components updated.

Runtime Monitoring

Behavioral monitoring - Detect unexpected process execution, file modifications, or network connections within containers.

Syscall monitoring - Track system calls for anomalous patterns indicating compromise.

Network monitoring - Observe container network traffic. Detect C2, lateral movement, or data exfiltration.

Log collection - Aggregate container and orchestrator logs. Forward to SIEM.

Detection Use Cases

Crypto mining - High CPU utilization, connections to mining pools.

Container escape attempts - Accessing host filesystems or attempting privileged operations.

Reverse shells - Unexpected outbound connections with interactive behavior.

Lateral movement - Container-to-container scanning or unauthorized access attempts.

Credential theft - Access to secrets or service account tokens beyond normal patterns.

Incident Response

Container incidents differ from traditional response:

Ephemerality - Containers may be short-lived. Capture state quickly.

Immutability - Rebuild rather than clean. Replace compromised containers from known-good images.

Orchestration - Incident may affect multiple containers. Understand scope in cluster context.

Evidence collection - Capture container filesystem, memory if possible, logs, and network captures.

Continuous Security

Drift detection - Identify runtime changes from expected configuration.

Compliance checking - Continuous assessment against security baselines.

Vulnerability updates - Track new CVEs affecting running containers. Prioritize remediation.

Security gates - Prevent deployment of non-compliant or vulnerable containers.