Group Policy Security Configuration

Group Policy enables consistent security configuration across Windows environments. Understanding GPO security settings helps implement hardening at scale.

Group Policy Architecture

Group Policy Objects (GPOs) contain settings applied to computers and users. GPOs link to organizational units (OUs), domains, or sites.

Processing order determines which settings apply: Local, Site, Domain, OU. Later policies override earlier ones. "No Override" and "Block Inheritance" modify this behavior.

Computer vs. User settings - Computer Configuration applies regardless of who logs in. User Configuration applies to specific users regardless of which computer they use.

Security-Relevant Settings

Password policies - Enforce complexity, length, history, and age requirements. Configure at domain level for consistent enforcement.

Account lockout policies - Lock accounts after failed authentication attempts. Balance security against denial-of-service risk.

Audit policies - Enable success and failure auditing for security-relevant events. Advanced Audit Policy Configuration provides granular control.

User rights assignments - Control who can perform privileged operations: log on locally, access the network, debug programs, take ownership.

Security options - Numerous settings affecting security behavior: LAN Manager authentication level, network security settings, User Account Control configuration.

Microsoft Security Baselines

Microsoft publishes security baselines with recommended GPO settings for Windows versions and roles. These baselines provide vetted starting points for hardening.

Security Compliance Toolkit includes baseline GPOs and comparison tools. Import baselines, compare against current configuration, and apply differences.

Regular baseline updates address new features and threats. Track baseline versions and update processes.

Testing and Deployment

Test thoroughly before production. GPO changes can break applications and workflows. Use test OUs or pilot deployments.

Document changes for troubleshooting and rollback.

Resultant Set of Policy (RSoP) shows effective settings on specific systems. Use gpresult to verify policy application.

GPO troubleshooting - Check event logs for processing errors. Verify network connectivity to domain controllers. Confirm OU placement and GPO links.