Safeguard 1.3: Utilize an Active Discovery Tool

Safeguard 1.3 requires you to run an active asset discovery capability that finds enterprise assets by probing the environment, then feed those results into your asset inventory and remediation workflow. To operationalize it fast, assign an owner, define scan scope and cadence, deploy an authenticated scanner where possible, reconcile results to your inventory, and track gaps to closure with retained evidence. ¹

Key takeaways:

• Active discovery means scanning your networks and environments to find assets you did not know you had, not just reviewing existing lists. ²
• Auditors will look for repeatable execution: defined scope, schedule, ownership, exception handling, and proof of results and follow-up. ²
• Treat discovery output as a control input: reconcile to inventory, investigate unknowns, and drive remediation tickets to validated closure.

Safeguard 1.3 sits inside CIS Control 1 (Inventory and Control of Enterprise Assets) and is aimed at a common failure mode: teams rely on CMDBs, procurement records, or cloud consoles and miss “drift” assets that quietly appear on networks. Active discovery closes that gap by continuously (or routinely) probing your environment for devices, systems, and endpoints so you can compare what is actually present against what is authorized and managed. ¹

For a Compliance Officer, CCO, or GRC lead, the fastest path is to translate this safeguard into one operational control with: a named control owner (usually Infrastructure, Security Operations, or IT Operations), a defined technical method (network scanning, endpoint discovery, cloud account discovery), a documented scan scope, and a reconciliation workflow that creates tickets for unknown or unmanaged assets. The compliance win is not the scanner itself. The win is evidence that the discovery runs on a defined cadence, the results are reviewed, discrepancies are resolved, and exceptions are governed rather than ignored. ²

This page gives requirement-level guidance to stand up Safeguard 1.3 quickly, with artifacts you can hand to an auditor and tasks an operator can run without guesswork.

Regulatory text

CIS Controls v8 excerpt (as provided): “CIS Controls v8 safeguard 1.3 implementation expectation (Utilize an Active Discovery Tool).” ¹

Operator interpretation: You must run an active discovery tool that identifies enterprise assets by actively probing your environment (for example, scanning networks or querying environments in a way that finds assets even if they are not already in your inventory). Then you must use those findings to keep your asset inventory accurate and to trigger response actions for unknown, unmanaged, or unauthorized assets. ²

What an assessor expects to see:

• A defined discovery method and tooling choice (what you scan, how you scan, and where results land).
• Demonstrated operation over time (recurring runs, not a one-time “project scan”).
• A reconciliation and remediation workflow (unknown assets get investigated and resolved). ²

Plain-English requirement: what it means

Safeguard 1.3: utilize an active discovery tool requirement means: “Don’t trust your spreadsheets or CMDB. Prove you can find assets that are connected or present, even when no one registered them, and prove you act on that information.”

Active discovery typically includes:

• Network discovery and port scanning on enterprise networks.
• Authenticated scanning where feasible (more accurate identification, better attribution).
• Discovery across segmented networks and remote locations where assets commonly evade oversight.

This safeguard is foundational. Every downstream control (patching, vulnerability management, EDR coverage, logging, access control) depends on knowing what exists.

Who it applies to

Entity scope: Enterprises, service organizations, and technology organizations implementing CIS Controls v8. ²

Operational scope (what to include):

• Corporate networks (office sites, data centers, colocation).
• Cloud environments (IaaS instances, managed endpoints, exposed services).
• Remote access segments (VPN address pools, VDI networks).
• High-risk enclaves (PCI/CDE-like segments, production networks, OT where applicable).

Who owns it (typical RACI):

• Control Owner: Infrastructure/SecOps (runs tools and triage).
• Accountable: CISO or Head of IT Operations (ensures coverage and resourcing).
• Consulted: Network team, Cloud platform team, Endpoint team, ITAM/CMDB owner.
• Informed: GRC (collects evidence, tracks exceptions).

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

Use this as an implementation runbook you can hand to an operator.

1) Create a control card (one page)

Document:

• Objective: detect and enumerate enterprise assets through active discovery.
• Owner and backup owner.
• Scope boundaries (networks/accounts included; explicit exclusions and why).
• Trigger events (new site, new VPC/VNet, M&A integration, new VLAN).
• Execution cadence (how often scans run; how you handle ad hoc scans).
• Exception rules (OT safety constraints, fragile systems, third-party managed segments).
  This aligns to the operational expectation that teams can show ownership, cadence, and evidence. ²

2) Define discovery scope and “coverage map”

Create a table that lists:

• Network ranges / segments
• Cloud accounts/subscriptions/projects
• Remote/branch connectivity patterns
• Tooling method per segment (agentless scan, authenticated scan, API-based discovery where applicable)

Keep it brutally explicit. If you cannot scan a segment, document the compensating approach (for example, upstream firewall logs plus DHCP logs plus NAC inventory) and track it as an exception with an end date.

3) Select and configure the active discovery method

Minimum operational configuration decisions:

• Scan type: unauthenticated discovery for breadth; authenticated where feasible for accuracy.
• Credential handling: vaulted credentials, rotation, least privilege.
• Safety controls: rate limits, exclusion lists, maintenance windows.
• Attribution fields: hostname, IP, MAC, cloud instance ID, owner tag if available.

Your goal is consistent identification so reconciliation is possible across runs.

4) Run the discovery and land results in a system of record

Treat scan output as controlled data:

• Store results in your security data lake, ticketing system, or asset management platform.
• Preserve raw outputs and a normalized “current asset list.”
• Record the run metadata: start/end time, scope scanned, scanner version/config, and operator (or automation identity).

5) Reconcile to the authorized inventory

Build a repeatable reconciliation workflow:

• Match discovered assets to existing inventory records.
• Flag unknowns (no matching record).
• Flag unmanaged (known asset exists, but missing endpoint agent, missing patch tooling, missing owner, missing tag).
• Flag unauthorized (present in a prohibited segment, rogue wireless, unexpected public exposure).

Output should be a tracked work queue, not an email.

6) Triage and remediate discrepancies

Define standard dispositions:

• Onboard: add to inventory, assign owner, apply baseline configuration, enroll in EDR/MDM.
• Remove/contain: isolate at network level, disable switch port, block at NAC, deprovision cloud resource.
• Validate false positive: document why it is not in scope or not an asset (test device, scanner artifact), then tune rules.

Track each item to validated closure with due dates. This matches the expectation to run recurring health checks and close remediation items. ²

7) Operationalize recurring control health checks

Add a lightweight monthly or quarterly control check (your choice) that answers:

• Did discovery run as scheduled?
• Did coverage change (new segments/accounts not yet added)?
• Are unknown assets trending down?
• Are exceptions still valid?

In practice, this is where many programs fail: the scanner keeps running, but nobody reviews results or exceptions.

Required evidence and artifacts to retain

Build a “minimum evidence bundle” per execution cycle. ²

Evidence bundle checklist

• Control card / runbook with owner, scope, cadence, and exceptions. ²
• Discovery scope register (networks/accounts scanned; exclusions with rationale).
• Tool configuration exports or screenshots: scan templates, target lists, credential vault integration, throttling settings.
• Scan run logs: timestamps, targets, completion status, error rates (qualitative is fine).
• Discovery results snapshot: list of assets discovered for that run (raw and normalized).
• Reconciliation output: report showing unknown/unmanaged/unauthorized assets.
• Tickets and closure evidence: ticket IDs, remediation actions taken, verification notes.
• Exception register: approved exclusions, owner, expiration/review date, compensating controls.

Retention location

• GRC repository for policies/control card and exceptions.
• Ticketing system for remediation workflow.
• Security tooling repository/SIEM/data lake for raw outputs and run logs.

Common exam/audit questions and hangups

Expect these in SOC 2, ISO 27001 surveillance audits, customer security reviews, and internal audit:

1. “Show me the last two runs and the scope.”
   Have run logs and the scope register ready.

2. “How do you know discovery covers all networks?”
   Provide a coverage map tied to your network inventory and cloud account list.

3. “What happens when you find something unknown?”
   Show your triage SOP and a sample ticket from detection to closure.

4. “Are scans authenticated? If not, why?”
   Explain technical constraints and show a plan or documented exceptions.

5. “How do you prevent scanning from disrupting operations?”
   Show throttling, maintenance windows, and exclusions for sensitive systems.

Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails	Fix
Treating the CMDB as “discovery”	It cannot find unregistered assets	Make scanning the source of truth for “what exists,” then reconcile into the CMDB
One-time network scan for an audit	Proves nothing about steady-state operation	Set an automated schedule and keep run logs 2
No owner, no triage queue	Findings pile up and get ignored	Assign a control owner and require ticketed closure 2
Scanning only HQ	Branch/remote networks become blind spots	Maintain a coverage map and onboard segments via trigger events
Unmanaged exceptions	Exclusions become permanent	Time-bound exceptions with periodic review and compensating controls

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this safeguard. The practical risk is still concrete: unknown assets routinely become unpatched, unmonitored entry points and complicate incident response because you cannot scope impact to systems you do not know exist. From a governance perspective, the primary audit failure mode is inability to show ownership, cadence, and traceable evidence that discovery results drove action. ²

Practical 30/60/90-day execution plan

Use phased execution without promising fixed completion dates; treat the milestones as outcome gates.

First 30 days (stand up the control)

• Assign control owner and backup; publish the control card. ²
• Build initial scope register: corporate IP ranges, primary cloud accounts, major sites.
• Pick the discovery method and define safe scanning standards (throttling, windows, exclusions).
• Run an initial baseline scan for the highest-value segments and store outputs.

Exit criteria: You can show one completed run, its scope, and where results are stored.

By 60 days (make it operational)

• Expand coverage to remaining in-scope segments; document exclusions and exceptions.
• Implement reconciliation: discovered assets compared to inventory, unknowns routed to a queue.
• Start ticket-driven remediation and track items to validated closure. ²
• Define control health check questions and reporting format.

Exit criteria: You can show at least one cycle where findings produced tickets and closed actions.

By 90 days (stabilize and prove repeatability)

• Automate recurring runs and reporting.
• Add trigger-event onboarding for new segments/accounts.
• Review exceptions; add compensating controls where scanning is constrained.
• Run a control health check and document outcomes and improvements. ²

Exit criteria: You can show recurring operation and that coverage stays current as the environment changes.

Where Daydream fits (practitioner view)

If your pain point is proof, not tooling, Daydream is most valuable as the control system around the scanner: control cards, evidence bundle definitions, recurring health checks, and remediation tracking mapped to Safeguard 1.3. That closes the “we run scans but can’t prove operation” gap auditors routinely focus on. ²

Frequently Asked Questions

Does “active discovery” require port scanning?

CIS Safeguard 1.3 requires an active discovery tool, which commonly includes network probing; your implementation can vary by environment. Document the method you chose and show it consistently finds assets not already in your inventory. ²

Do we need authenticated scanning to meet the safeguard?

The safeguard does not mandate authenticated scanning in the provided excerpt, but assessors often expect you to use authentication where feasible because it improves asset identification. If you cannot, document the constraint and your compensating process for accurate identification. ²

How do we handle sensitive environments where scanning could cause outages?

Put those segments into an exception register with an approved rationale, bounded scope, and a compensating discovery approach (for example, NAC/DHCP inventory plus strict allowlisting). Revisit exceptions during control health checks. ²

What’s the minimum evidence an auditor will accept?

Keep a control card, scope register, proof of scan runs, a results snapshot, and examples showing reconciliation and remediation tickets closed. Evidence should show repeatable operation, not a one-off report. ²

How do we treat cloud assets where “scanning” is not straightforward?

Define cloud discovery methods in your scope register (network-based where applicable, plus cloud-native inventory sources where needed) and reconcile those results into your asset inventory workflow. Keep the same triage and ticketing steps for unknown or unauthorized assets. ²

Who should own Safeguard 1.3: utilize an active discovery tool requirement?

Assign ownership to the team that can run discovery and act on results, usually Infrastructure or SecOps. GRC should oversee evidence quality, exceptions, and whether remediation is tracked to closure. ²

Footnotes

1. CIS Controls v8; CIS Controls Navigator v8

2. CIS Controls v8