Requirement text: RM.2.142: Scan for vulnerabilities in organizational systems and applications
periodically and when new vulnerabilities affecting those systems and applications are identified.
DISCUSSION FROM SOURCE: 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.
CMMC CLARIFICATION
A vulnerability scanner is an application that identifies an organization’s asset
vulnerabilities for which the scanner is capable of identifying. Then, the scanner creates a
prioritized list of asset vulnerabilities ordered by their level of severity. The scanner also
describes each vulnerability and the steps needed to fix it. Your organization should scan for
vulnerabilities on all devices connected to the network. This includes servers, desktops,
laptops, virtual machines, containers, firewalls, switches, and printers. All assets that have
any form of connection to a wired network, Wi-Fi environment, and air-gapped labs that are
associated with the CMMC assessment should be scanned.
Organizations that develop custom software should perform reviews of the software.
Vulnerability analysis of a custom-made solution requires an experienced penetration tester
to properly test and validate findings. Automated vulnerability scanners do not necessarily
perform well against custom developed applications.
The vulnerability scanning process should be a regular activity. It should not be a single
occurrence. Organizations should put in place a vulnerability scanner that updates its
database each time it performs a scan. This means that the scan looks for the most current
vulnerabilities. Schedule scans with consideration of the potential for impact to normal
operations. Use caution when scanning critical assets. These assets do need to be scanned,
but some scanning options could cause a denial of service against a critical asset. You could
replicate the critical asset in a test environment and perform vulnerability scans against the
replicated asset. The replicated asset vulnerability scan will produce valid reports that need
to be applied to the production system only if the replicated system is an exact duplicate of
the production system and has identical functionality in operation when being tested.
Example
You are in charge of IT in your organization. You look for errors in your software that may
provide ways for hackers to get into your network and do harm. You perform vulnerability
scans to try and find these errors. You use a vulnerability scanner application that tests all
the assets connected to your network. As a result of the scan, you get a prioritized list of
vulnerabilities. Because you will scan everything connected to your network, you should set
up the scan to happen at night. You should also make sure that your vulnerability scanner
application gets updated on a regular basis.
References
• NIST SP 800-171 Rev 1 3.11.2
• CIS Controls v7.1 3.1, 3.2
• NIST CSF v1.1 ID.RA-1
• CERT RMM v1.2 VAR:SG2.SP2
• NIST SP 800-53 Rev 4 RA-5