19. Secure Configuration and Audit Automation

This chapter pulls earlier permissions, environment, services, logs, and remote-access skills into repeatable host audit scripts.

• Permissions: Audit risky modes and ownership.

• Accounts: Review users and groups.

• Secrets: Search carefully for accidental exposure.

• Integrity: Record file hashes and changes.

• Hardening: Report configuration issues before changing them.

Chapter Video

How Secure Is Your Linux Server? Test It with This Free Audit Tool (16:30) by David Bombal

Hosted on YouTube; property of its original creator, embedded here for educational reference only.

Learning Objectives

By the end of this chapter, you will be able to:

1. Write read-only permission audit checks.

2. Inspect users, groups, and selected configuration files.

3. Look for accidental secret exposure in authorized lab files.

4. Summarize SSH and service configuration findings.

5. Produce a clear audit report.

Chapter Flow

1. Permission Audits

2. Account and SSH Checks

3. Secrets and Integrity Checks

4. Audit Reports

Glossary

#	Term	Explanation
1	audit	Systematic inspection.
2	hardening	Reducing avoidable risk.
3	least privilege	Granting only needed access.
4	secret	Sensitive credential or token.
5	file integrity	Evidence that file content stayed unchanged.
6	configuration drift	Unexpected change from desired settings.
7	finding	Reported issue or observation.
8	false positive	Benign item reported as suspicious.
9	remediation	Action taken to fix a finding.
10	scope	Boundary of an authorized audit.