Purpose

This example is a controlled Ubuntu lab. It contains sample configuration, local test data, an analysis script and a run.sh that performs static checks and evidence generation.

Local Check

./run.sh

Learning Goals

• trace Ubuntu configuration
• review service, network and security artifacts
• evaluate logs and package plan
• inspect evidence files
• derive review rules

Files

• bin/ufw_firewall_baseline.sh
• config/systemd/workshop-health.service
• config/netplan/01-workshop.yaml
• config/security/sshd_baseline.conf
• baseline.json

Review Checklist for UFW Firewall Baseline

• 01. check release and support status: Record the affected host, package, service, configuration and risk.
• 02. evaluate package and repository risk: Record the affected host, package, service, configuration and risk.
• 03. explain service status and logs: Record the affected host, package, service, configuration and risk.
• 04. document network assumption: Record the affected host, package, service, configuration and risk.
• 05. review user and sudo rule: Record the affected host, package, service, configuration and risk.
• 06. evaluate firewall rule and exposure: Record the affected host, package, service, configuration and risk.
• 07. describe storage and backup path: Record the affected host, package, service, configuration and risk.
• 08. record patch and reboot window: Record the affected host, package, service, configuration and risk.
• 09. mark security baseline: Record the affected host, package, service, configuration and risk.
• 10. name monitoring or alert rule: Record the affected host, package, service, configuration and risk.
• 11. record rollback or recovery path: Record the affected host, package, service, configuration and risk.
• 12. write team rule: Record the affected host, package, service, configuration and risk.
• 13. check release and support status: Record the affected host, package, service, configuration and risk.
• 14. evaluate package and repository risk: Record the affected host, package, service, configuration and risk.
• 15. explain service status and logs: Record the affected host, package, service, configuration and risk.
• 16. document network assumption: Record the affected host, package, service, configuration and risk.
• 17. review user and sudo rule: Record the affected host, package, service, configuration and risk.
• 18. evaluate firewall rule and exposure: Record the affected host, package, service, configuration and risk.
• 19. describe storage and backup path: Record the affected host, package, service, configuration and risk.
• 20. record patch and reboot window: Record the affected host, package, service, configuration and risk.
• 21. mark security baseline: Record the affected host, package, service, configuration and risk.
• 22. name monitoring or alert rule: Record the affected host, package, service, configuration and risk.
• 23. record rollback or recovery path: Record the affected host, package, service, configuration and risk.
• 24. write team rule: Record the affected host, package, service, configuration and risk.
• 25. check release and support status: Record the affected host, package, service, configuration and risk.
• 26. evaluate package and repository risk: Record the affected host, package, service, configuration and risk.
• 27. explain service status and logs: Record the affected host, package, service, configuration and risk.
• 28. document network assumption: Record the affected host, package, service, configuration and risk.
• 29. review user and sudo rule: Record the affected host, package, service, configuration and risk.
• 30. evaluate firewall rule and exposure: Record the affected host, package, service, configuration and risk.
• 31. describe storage and backup path: Record the affected host, package, service, configuration and risk.
• 32. record patch and reboot window: Record the affected host, package, service, configuration and risk.
• 33. mark security baseline: Record the affected host, package, service, configuration and risk.
• 34. name monitoring or alert rule: Record the affected host, package, service, configuration and risk.
• 35. record rollback or recovery path: Record the affected host, package, service, configuration and risk.
• 36. write team rule: Record the affected host, package, service, configuration and risk.
• 37. check release and support status: Record the affected host, package, service, configuration and risk.
• 38. evaluate package and repository risk: Record the affected host, package, service, configuration and risk.
• 39. explain service status and logs: Record the affected host, package, service, configuration and risk.
• 40. document network assumption: Record the affected host, package, service, configuration and risk.
• 41. review user and sudo rule: Record the affected host, package, service, configuration and risk.
• 42. evaluate firewall rule and exposure: Record the affected host, package, service, configuration and risk.
• 43. describe storage and backup path: Record the affected host, package, service, configuration and risk.
• 44. record patch and reboot window: Record the affected host, package, service, configuration and risk.

Practice Appendix: UFW Firewall Baseline

This appendix is a working backlog for longer trainings, reviews and repetitions. Each task can be checked locally with sample configuration, shell commands and a Git repository.

A001. Default-Deny und Portfreigaben

• Task: check release and support status and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A002. Ubuntu

• Task: evaluate package and repository risk and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A003. Operations

• Task: explain service status and logs and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A004. Security

• Task: document network assumption and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A005. Default-Deny und Portfreigaben

• Task: review user and sudo rule and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A006. Ubuntu

• Task: evaluate firewall rule and exposure and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A007. Operations

• Task: describe storage and backup path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A008. Security

• Task: record patch and reboot window and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A009. Default-Deny und Portfreigaben

• Task: mark security baseline and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A010. Ubuntu

• Task: name monitoring or alert rule and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A011. Operations

• Task: record rollback or recovery path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A012. Security

• Task: write team rule and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A013. Default-Deny und Portfreigaben

• Task: check release and support status and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A014. Ubuntu

• Task: evaluate package and repository risk and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A015. Operations

• Task: explain service status and logs and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A016. Security

• Task: document network assumption and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A017. Default-Deny und Portfreigaben

• Task: review user and sudo rule and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A018. Ubuntu

• Task: evaluate firewall rule and exposure and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A019. Operations

• Task: describe storage and backup path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A020. Security

• Task: record patch and reboot window and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A021. Default-Deny und Portfreigaben

• Task: mark security baseline and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A022. Ubuntu

• Task: name monitoring or alert rule and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A023. Operations

• Task: record rollback or recovery path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A024. Security

• Task: write team rule and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A025. Default-Deny und Portfreigaben

• Task: check release and support status and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A026. Ubuntu

• Task: evaluate package and repository risk and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A027. Operations

• Task: explain service status and logs and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A028. Security

• Task: document network assumption and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A029. Default-Deny und Portfreigaben

• Task: review user and sudo rule and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A030. Ubuntu

• Task: evaluate firewall rule and exposure and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A031. Operations

• Task: describe storage and backup path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A032. Security

• Task: record patch and reboot window and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A033. Default-Deny und Portfreigaben

• Task: mark security baseline and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A034. Ubuntu

• Task: name monitoring or alert rule and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A035. Operations

• Task: record rollback or recovery path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A036. Security

• Task: write team rule and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A037. Default-Deny und Portfreigaben

• Task: check release and support status and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A038. Ubuntu

• Task: evaluate package and repository risk and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A039. Operations

• Task: explain service status and logs and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A040. Security

• Task: document network assumption and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A041. Default-Deny und Portfreigaben

• Task: review user and sudo rule and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A042. Ubuntu

• Task: evaluate firewall rule and exposure and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A043. Operations

• Task: describe storage and backup path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A044. Security

• Task: record patch and reboot window and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A045. Default-Deny und Portfreigaben

• Task: mark security baseline and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A046. Ubuntu

• Task: name monitoring or alert rule and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A047. Operations

• Task: record rollback or recovery path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A048. Security

• Task: write team rule and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A049. Default-Deny und Portfreigaben

• Task: check release and support status and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A050. Ubuntu

• Task: evaluate package and repository risk and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A051. Operations

• Task: explain service status and logs and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A052. Security

• Task: document network assumption and connect the observation explicitly to Security.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A053. Default-Deny und Portfreigaben

• Task: review user and sudo rule and connect the observation explicitly to Default-Deny und Portfreigaben.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A054. Ubuntu

• Task: evaluate firewall rule and exposure and connect the observation explicitly to Ubuntu.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.

A055. Operations

• Task: describe storage and backup path and connect the observation explicitly to Operations.
• Evidence: Record at least one Ubuntu-related command, expected output and a boundary of that evidence.
• Operations question: What would a wrong assumption cause in dev, staging, prod and CI?
• Security question: Which accounts, services, packages, ports, logs or secrets would be critical?
• Recovery: Describe whether rollback, restore, package downgrade, reboot, key rotation or manual correction would be needed.