03.11.02: Vulnerability Monitoring and Scanning

To meet the 03.11.02: vulnerability monitoring and scanning requirement, you must continuously watch for vulnerabilities across the systems that handle CUI, run authenticated vulnerability scans on a defined cadence and after material changes, triage findings by risk, and track remediation to closure with evidence. Treat this as an operational program, not a quarterly report ¹.

Key takeaways:

• Define scan scope from your CUI boundary, asset inventory, and exposure points, then keep it current ¹.
• Run credentialed scans, validate results, and drive a documented remediation workflow with SLAs and exception handling ¹.
• Keep auditor-ready artifacts: schedules, configurations, results, tickets, approvals, and metrics that prove the control operated ¹.

03.11.02 sits in the Vulnerability Management family of NIST SP 800-171 Rev. 3 and is assessed as a “show me” control. Assessors typically do not accept “we scan” as an answer; they want proof that you (1) know what is in scope for CUI, (2) scan it in a repeatable way, (3) prioritize and fix what you find, and (4) can demonstrate the program ran consistently over time ¹.

Operationalizing this requirement quickly starts with scope discipline. Your scanning program must match the actual CUI environment: endpoints, servers, network devices, cloud workloads, container images, and externally exposed services. Next, you need a tight workflow from detection to remediation, including false-positive handling, compensating controls, and risk acceptance approvals. Finally, you need evidence: scan configurations, scan coverage, dated results, and closure records that trace high-risk findings to fixes. This page gives requirement-level guidance you can put into a control, run weekly, and defend in an assessment ¹.

Regulatory text

Requirement: “NIST SP 800-171 Rev. 3 requirement 03.11.02 (Vulnerability Monitoring and Scanning).” ¹

Operator interpretation: You must implement a vulnerability monitoring and scanning capability for in-scope systems (those that process, store, or transmit CUI), then prove it operates as a recurring control. “Monitoring” covers staying aware of new vulnerabilities relevant to your technology stack. “Scanning” covers running technical checks to identify vulnerabilities in your environment and acting on results ¹.

Plain-English interpretation (what the requirement really demands)

You need a repeatable way to:

1. Know what to scan (authoritative inventory tied to the CUI boundary).
2. Scan it reliably (credentialed scanning where feasible, with defined frequency and triggers).
3. Turn findings into fixes (triage, assign ownership, remediate, verify).
4. Control exceptions (document false positives, risk acceptance, and compensating controls).
5. Keep evidence that proves the above happened over time ¹.

If your scans don’t cover the CUI boundary, or you can’t show closure, assessors will treat the control as ineffective even if a tool is installed.

Who it applies to (entity and operational context)

Applies to: Nonfederal organizations handling CUI for U.S. Government contracts, including federal contractors and any nonfederal system components that process, store, or transmit CUI ¹.

Operational scope typically includes:

• User endpoints used to access CUI systems
• Servers (on-prem or cloud) hosting CUI applications and data
• Network devices supporting the CUI boundary (firewalls, VPN, routers, switches)
• Cloud control plane configurations relevant to CUI workloads
• Internet-facing services that connect to or front the CUI environment
• Third-party–hosted components that are part of your CUI system boundary (your responsibility is governance plus evidence of coverage, even if the scanning is performed by a third party) ¹

What you actually need to do (step-by-step)

1) Define scope from the CUI boundary

• Identify the CUI system boundary (networks, accounts, workloads, endpoints).
• Map asset groups: “CUI endpoints,” “CUI servers,” “CUI network,” “CUI cloud workloads,” “Internet-facing.”
• Write a one-page scan scope statement tied to your boundary diagram and inventory ¹.

Practical tip: If you have multiple enclaves, treat each enclave as a scan target group with a named owner.

2) Stand up vulnerability “monitoring” (intake)

Create a lightweight vulnerability intelligence process:

• Subscribe to vendor/security advisories for your core stack (OS, hypervisor, VPN, firewall, EDR, key applications).
• Track “relevant to us” determinations (a simple log is enough).
• Define who reviews advisories and how urgent items trigger out-of-cycle scans or emergency patching ¹.

3) Implement scanning mechanics that produce defensible results

• Prefer authenticated (credentialed) scanning for servers and endpoints, where feasible.
• Include configuration where needed: scan templates, safe checks, timeout rules, and exclusions.
• Cover external attack surface: scan internet-facing IPs/domains tied to the CUI environment.
• Define scan triggers:
  • Recurring scans (your cadence)
  • After major changes (new subnet, new images, significant version upgrades)
  • After high-severity advisories relevant to your stack ¹

Decision point: If a segment cannot be scanned (legacy OT, isolated lab), document the reason and implement an alternate detection method plus compensating controls.

4) Normalize and triage findings

Build a standard triage flow:

• Validate finding accuracy (false positives happen).
• Assign severity and exploitability context (use your internal risk method; keep it consistent).
• Identify the remediation owner (system owner, app owner, platform team).
• Open a ticket for each remediable item (or a grouped ticket for a patch set) with:
  • Asset
  • Finding ID/CVE (if available)
  • Required action
  • Due date based on severity (your internal SLA)
  • Exception path ¹

5) Remediate, verify, and close the loop

• Patch, mitigate, or remove vulnerable services.
• Re-scan or otherwise verify remediation.
• Close tickets only after verification evidence exists (scan shows fixed, configuration change confirmed, or compensating control approved).
• Track aging items and require periodic review of open high-risk findings ¹.

6) Govern exceptions without breaking the control

You will have exceptions. Make them auditable:

• False positive: document validation steps and suppress with approval.
• Risk acceptance: document business justification, duration, compensating controls, and approval by the right authority (often the system owner plus security).
• Deferred remediation: document dependency, plan, and interim mitigations ¹.

7) Build assessment-ready reporting

Prepare recurring views:

• Coverage: assets in scope vs assets scanned
• Findings by severity and aging
• SLA performance (your internal targets)
• Repeat offenders and root causes (patching gaps, unmanaged assets) ¹

Where Daydream fits: Many teams fail this control on evidence, not intent. Daydream can help you map 03.11.02 to a written policy/control, then automate recurring evidence collection (scan schedules, exports, tickets, exception approvals) so your assessment package stays current ¹.

Required evidence and artifacts to retain

Keep artifacts that prove both design and operation:

• Vulnerability management policy/standard referencing 03.11.02 ¹
• CUI boundary diagram and scan scope statement ¹
• Asset inventory extracts showing in-scope systems ¹
• Scan configurations: credentialed scan settings, templates, exclusions with approvals ¹
• Scan schedules and run logs (dates/times, targets, success/failure) ¹
• Scan reports and raw exports (retain enough history to show ongoing operation) ¹
• Ticketing evidence: triage notes, assignments, remediation actions, closure proof ¹
• Exception register: risk acceptances, false positives, compensating controls, approvals ¹
• Metrics snapshots used for management review ¹

Common exam/audit questions and hangups

Assessors often ask:

• “Show me your CUI boundary and how scan scope maps to it.” ¹
• “Are scans authenticated? If not, why, and what do you miss?” ¹
• “How do you know scans ran as scheduled? Show evidence of successful completion.” ¹
• “Pick a high-risk finding. Walk me from discovery to closure.” ¹
• “How do you handle systems managed by a third party or hosted in cloud services?” ¹
• “Show your exception approvals and review cadence.” ¹

Hangups that cause findings:

• Asset inventory doesn’t match scan targets.
• Scans run, but remediation is informal (no tickets, no owners, no deadlines).
• Exclusions are undocumented and too broad.

Frequent implementation mistakes (and how to avoid them)

1. Scanning only internal IP ranges and calling it done
   Fix: Add external scanning of internet-facing assets tied to the CUI environment ¹.

2. Unauthenticated scanning of servers
   Fix: Use credentialed scans for OS and application patch visibility; document exceptions where credentials are not feasible ¹.

3. No defined “out-of-band” trigger
   Fix: Add a trigger for high-impact advisories relevant to your stack and major environment changes ¹.

4. Overreliance on tool dashboards with no retained evidence
   Fix: Export and retain scan results and run logs; store them in an evidence repository tied to the control ¹.

5. Exception handling by email or chat
   Fix: Use a formal exception register with approvals, expiration, and compensating controls ¹.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this specific requirement. Practically, failure modes for 03.11.02 increase the chance that known vulnerabilities persist in CUI environments, which can lead to unauthorized access and reporting obligations under contract and incident requirements tied to CUI handling ¹.

Practical 30/60/90-day execution plan

First 30 days (stabilize scope and get repeatable scans running)

• Define CUI boundary and in-scope asset groups ¹.
• Choose scanning approach per segment (endpoints, servers, network, cloud) and confirm credentialed scanning plan ¹.
• Run baseline scans, document failures, fix access issues, and produce first triage queue ¹.
• Stand up ticket workflow and exception register ¹.

Days 31–60 (operationalize remediation and reporting)

• Set severity-based remediation SLAs (internal policy decision) and enforce ownership ¹.
• Implement weekly triage meeting or async review with documented outcomes ¹.
• Add external scanning for internet-facing assets and validate results ¹.
• Produce management metrics and keep snapshots as evidence ¹.

Days 61–90 (prove maturity and assessment readiness)

• Test change-triggered scanning on a real change (new workload or major patch cycle) and retain evidence ¹.
• Audit your own coverage: inventory vs scan targets vs scan success rate, then close gaps ¹.
• Run an internal “sample walk-through” for an assessor: pick findings, show closure evidence, show exceptions ¹.
• If evidence collection is manual, implement Daydream workflows to collect exports, tickets, and approvals on a recurring schedule aligned to 03.11.02 ¹.

Frequently Asked Questions

Do we need credentialed (authenticated) scans to satisfy 03.11.02?

The requirement text in the provided excerpt does not specify credentialed scanning, but assessors commonly expect scanning to be effective. Credentialed scans are a standard way to produce reliable OS and patch visibility, and you should document any segments where credentials are not feasible ¹.

What assets are “in scope” for vulnerability monitoring and scanning?

Anything within, or security-relevant to, the system boundary that processes, stores, or transmits CUI is in scope. Start from your CUI boundary and inventory, then include supporting infrastructure and any internet-facing entry points connected to the environment ¹.

How do we handle third-party–hosted systems (SaaS/IaaS) that touch CUI?

You still need evidence that vulnerability monitoring and scanning occurs for the CUI boundary. Depending on responsibility, this can include your own scanning of what you manage plus third-party attestations, reports, or tickets that demonstrate coverage for what they manage ¹.

What evidence is most persuasive in an assessment?

A tight chain: scan schedule and run logs, scan outputs, tickets with remediation actions, and verification scans showing closure. Add an exception register with approvals for anything not remediated ¹.

We scan regularly, but we can’t fix everything quickly. Is that automatically noncompliant?

Not automatically, but you need governance. Keep severity-based SLAs, documented remediation plans, interim mitigations, and formal risk acceptance where you defer remediation beyond your targets ¹.

How can Daydream help without turning this into a paperwork exercise?

Use Daydream to map 03.11.02 to a clear control statement and automate recurring evidence pulls from your scanner, ticketing system, and exception approvals. That keeps the evidence package current while your engineers focus on remediation work ¹.

Footnotes

1. NIST SP 800-171 Rev. 3