The Essential Guide to NIST SP 800-171: Configuration Management

Understanding Configuration Management

For government contractors, compliance with NIST SP 800-171 is not optional—it is a critical requirement. Properly preparing for these security mandates ensures business continuity and protects against cyber threats. This guide explores the key role of Configuration Management in securing Controlled Unclassified Information (CUI) and strengthening cyber resilience.

Configuration Management is essential in cybersecurity, ensuring systems are properly maintained and protected against evolving threats. NIST SP 800-171 establishes specific requirements to secure sensitive government-related data and maintain the integrity of IT systems.

NIST SP 800-171 Configuration Management Requirements

• Baseline Configurations and System Inventories (3.4.1). Establishing and maintaining a documented baseline configuration is essential for tracking hardware, software, and firmware across an organization’s IT environment. Regular updates prevent vulnerabilities and ensure system integrity.

• Security Configuration Settings (3.4.2). Organizations must enforce security settings that harden systems against cyber threats. Secure configurations must be applied to operating systems, applications, and network devices to prevent unauthorized access.

• Change Tracking and Approval Processes (3.4.3). System changes must be documented, reviewed, approved, and logged to maintain compliance and ensure proper oversight of IT modifications.

Security Analysis and Enforcement

• Security Impact Analysis (3.4.4). Before implementing changes, organizations must assess potential security impacts. System administrators and security officers should conduct thorough risk evaluations to ensure compliance.

• Access Restrictions for System Changes (3.4.5). Only authorized personnel should be permitted to modify system configurations. Organizations must implement physical and logical access controls to manage and monitor changes effectively.

• Applying Least Functionality Principles (3.4.6). Organizations should configure systems to provide only essential functions, reducing the risk of cyberattacks. This involves eliminating unnecessary applications, services, and ports.

Reducing the Attack Surface

• Restricting Nonessential Functions (3.4.7). Disabling or preventing the use of nonessential programs, services, and ports reduces vulnerabilities and attack vectors. Best practices include controlling execution privileges and disabling features like Bluetooth, FTP, and peer-to-peer networking.

• Apply Reject Listing or Allow Listing (3.4.8). Organizations can choose between reject listing (deny-by-exception) and allow listing (permit-by-exception). Reject listing identifies what software programs are not authorized to execute on systems. It is the easier and more flexible way for allowing exceptions on a needed basis. The second approach, allow listing, is the stronger and more secure approach. It explicitly approves which applications can run, simultaneously reducing the risk of unauthorized software execution. 

• User-Installed Software Control (3.4.9). Strict policies should govern software installations, limiting them to pre-approved sources and blocking unverified or potentially malicious applications. Permitted software installations include updates and security patches to existing software from organization-approved “app stores.” Prohibited software installations include unknown or suspicious software or software that organizations consider potentially malicious.

Ensuring NIST SP 800-171 Compliance for DoD Contracts

Total Assure leverages decades of cybersecurity expertise to help organizations achieve NIST SP 800-171 compliance. Our tailored security solutions align with business operations to mitigate risks, detect vulnerabilities, and ensure adherence to regulatory frameworks such as DFARS, FISMA, and FedRAMP.