CMMC Practice RM.2.142
Scan for vulnerabilities in organizational systems and applications periodically and when new vulnerabilities affecting those systems and applications are identified.
Bold Coast Security Guidance
For Level 1 compliance you'll need a practice in place to regularly scan your environment for vulnerabilities. This practice is also valuable to ensure your patch management practice is effective, because vulnerability scanners also identify missing patches. For Level 2 compliance, you'll need a policy requiring the practice and a consistent schedule for when scans are performed.
DRAFT NIST SP 800-171 R2
Organizations determine the required vulnerability scanning for all system components, ensuring that potential sources of vulnerabilities such as networked printers, scanners, and copiers are not overlooked. The vulnerabilities to be scanned are readily updated as new vulnerabilities are discovered, announced, and scanning methods developed. This process ensures that potential vulnerabilities in the system are identified and addressed as quickly as possible. Vulnerability analyses for custom software applications may require additional approaches such as static analysis,dynamic analysis, binary analysis, or a hybrid of the three approaches. Organizations can employ these analysis approaches in source code reviews and in a variety of tools (e.g., static analysis tools, web -based application scanners, binary analyzers) and in source code reviews. Vulnerability scanning includes: scanning for patch levels; scanning for functions, ports, protocols, and services that should not be accessible to users or devices; and scanning for improperly configured or incorrectly operating information flow control mechanisms.
To facilitate interoperability, organizations consider using products that are Security Content Automated Protocol (SCAP)-validated, scanning tools that express vulnerabilities in the Common Vulnerabilities and Exposures (CVE) naming convention, and that employ the Open Vulnerability Assessment Language (OVAL) to determine the presence of system vulnerabilities. Sources for vulnerability information include the Common Weakness Enumeration (CWE) listing and the National Vulnerability Database (NVD). Security assessments, such as red team exercises, provide additional sources of potential vulnerabilities for which to scan. Organizations also consider using scanning tools that express vulnerability impact by the Common Vulnerability Scoring System (CVSS). In certain situations, the nature of the vulnerability scanning may be more intrusive or the system component that is the subject of the scanning may contain highly sensitive information. Privileged access authorization to selected system components facilitates thorough vulnerability scanning and protects the sensitive nature of such scanning.
NIST SP 800-40 provides guidance on vulnerability management.