Here are the 50 practical scenarios on how to manage security in linux that can help you prepare for the RHSA (Red Hat Certified System Administrator) exam:
User and Group Security:
1. Create a new user with a specific username and home directory.
2. Set a password policy for user accounts, including password complexity requirements.
3. Change the password for a user account.
4. Disable a user account.
5. Manage user account expiration and locking policies.
6. Create a new group and add users to it.
7. Configure user and group ownership for files and directories.
File and Directory Permissions:
8. Modify file permissions to allow read, write, and execute access for specific users and groups.
9. Restrict file access by removing permissions for specific users.
10. Set the setuid, setgid, and sticky bits on files and directories.
11. Use Access Control Lists (ACLs) to grant and restrict file access.
12. View and interpret file permission settings.
Authentication and Authorization:
13. Configure the system to use LDAP for user authentication.
14. Set up SSH key-based authentication for a user.
15. Implement password policies using Pluggable Authentication Modules (PAM).
16. Configure sudo to allow specific users to execute commands as root.
17. Create and manage sudoers rules for fine-grained access control.
18. Monitor authentication logs for failed login attempts.
SELinux Configuration:
19. Set SELinux to permissive mode for troubleshooting.
20. Check SELinux status and the SELinux mode.
21. Restore default SELinux file contexts on a file or directory.
22. Create and apply custom SELinux policy modules.
23. Troubleshoot and resolve SELinux-related issues.
24. Check audit logs for SELinux denials.
Firewall and Network Security:
25. Create a custom firewall rule using firewalld or iptables.
26. Allow or deny incoming traffic on specific ports.
27. Restrict access to services using firewalld zones.
28. Configure Network Address Translation (NAT) using iptables.
29. Set up a basic network intrusion detection system (NIDS).
30. Configure and test firewall rules for a specific service (e.g., HTTP, SSH).
Security Updates and Patch Management:
31. Configure the system to automatically check for and apply security updates.
32. View available updates without installing them.
33. Install only security updates using a package manager (e.g., yum or dnf).
34. Create a repository configuration file for custom package sources.
35. Review and analyze system vulnerabilities using a vulnerability scanner (e.g., OpenSCAP).
Logging and Auditing:
36. Configure the system to store logs in a centralized location (e.g., rsyslog).
37. Set up auditd for system auditing and monitoring.
38. Generate and view audit reports using audit tools.
39. Monitor system logs for suspicious activities and security events.
40. Set up log rotation and retention policies for log files.
Secure Communication:
41. Generate SSL/TLS certificates for securing web services.
42. Configure Apache or Nginx to use SSL/TLS for encrypted web communication.
43. Create an SSH tunnel for secure remote access.
44. Implement secure email communication using encryption (e.g., GPG).
45. Securely transfer files using SCP or SFTP.
Access Control Lists (ACLs):
46. Create and modify ACLs for files and directories.
47. Grant and restrict access to specific users and groups using ACLs.
48. View and interpret ACL settings on files and directories.
49. Remove ACL entries from files and directories.
50. Troubleshoot permission issues using ACLs.
Note : These scenarios cover a wide range of security-related tasks and concepts, which are essential for managing security in a Linux environment. Practice these tasks on a Red Hat-based system to prepare for the RHSA exam and real-world security administration challenges.
