SI-3(2): Automatic Updates

SI-3(2): Automatic Updates sits in the System and Information Integrity family and is easy to “say you do” but hard to prove under assessment pressure. Most findings are not about whether you own endpoint protection. They are about whether updates are truly automatic, consistently enforced, and measurably effective across all in-scope assets, including remote endpoints, servers with tight change windows, and disconnected or restricted networks.

For a CCO, GRC lead, or Compliance Officer, the fastest path is to define the scope of “malicious code protection mechanisms” in your environment, lock in a single operating standard for automatic updates, and build an evidence trail that shows (1) the configuration requirement, (2) the rollout and enforcement, (3) ongoing monitoring, and (4) exceptions with compensating controls. This page gives you requirement-level implementation guidance you can hand to security operations and then test as a control owner.

Target keyword: si-3(2): automatic updates requirement.

Regulatory text

Excerpt: “NIST SP 800-53 control SI-3.2.” ¹

What the operator must do: Implement automatic update capability for the mechanisms you rely on to detect and block malicious code (for example, endpoint protection/anti-malware signatures, engines, and related detection content), and operate it as a managed control with continuous oversight and evidence. The intent is to reduce exposure created by stale detection content and inconsistent manual updating. ¹

Practical framing for audits: you are being assessed on (a) configuration (automatic updates enabled), (b) coverage (applies broadly to in-scope assets), and (c) operational effectiveness (you detect failures and remediate them). ¹

Plain-English interpretation (what SI-3(2) means day-to-day)

SI-3(2): Automatic Updates requires your anti-malware and related malicious code protections to update themselves without humans pushing buttons. You still need governance: define what “automatic” means for your environment, enforce settings centrally, and monitor update status so that failures (offline devices, broken agents, blocked update URLs) do not silently accumulate.

This is a control where “we set it once” is rarely enough. Endpoints go off network. Servers run change freezes. Third-party managed devices appear. SI-3(2) expects you to manage those realities with update channels, health checks, and documented exceptions.

Who it applies to (entity and operational context)

Entity types typically in scope:

• Federal information systems and programs adopting NIST SP 800-53 controls. ²
• Contractor systems handling federal data where NIST 800-53 is flowed down by contract, ATO boundary, or customer security requirements. ²

Operational contexts where assessors focus:

• End-user endpoints (corporate and BYOD if in scope).
• Servers (including domain controllers, file servers, application servers).
• Virtual workloads and cloud instances (gold images, ephemeral hosts).
• Restricted enclaves (no direct internet, staged updates).
• Third-party managed endpoints or co-managed tooling where your organization still bears compliance responsibility.

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

Use this as a build sheet for the control owner. Keep steps tightly mapped to evidence.

Step 1: Define the “malicious code protection mechanisms” in scope

1. Inventory the tools and features you rely on to prevent/detect malicious code (endpoint protection platform, anti-malware engines, signature feeds, behavioral rules, EDR content updates).
2. Map each mechanism to covered asset classes (workstations, servers, VDI, containers, cloud workloads).
3. Decide what “update” means for each mechanism (engine version, signature definitions, detection rules, threat intel feeds).

Output: a scope statement and tooling list attached to the control narrative.

Step 2: Set the automatic update standard (policy + configuration baseline)

1. Write a short standard: “All in-scope malicious code protection mechanisms must be configured for automatic updates from an approved update source.”
2. Define approved update sources (direct vendor cloud, internal update relay, WSUS-like proxy, offline package repository).
3. Define “update health” expectations:
   • Device reports current update status.
   • Update failures generate an alert/ticket.
   • Exceptions require approval and compensating controls.

Operator tip: Keep this standard implementation-agnostic so it survives tooling changes. The baseline lives in configuration management.

Step 3: Implement centralized enforcement

1. Configure your central console (or MDM/endpoint management) to enforce automatic updates.
2. Prevent local override where feasible (role-based access, tamper protection).
3. For servers with controlled maintenance windows, set an automatic update schedule that fits change control but does not require manual action for each update cycle.
4. For disconnected networks, implement “automatic within the enclave” by staging updates to an internal repository that endpoints pull from automatically.

What auditors look for: centrally verifiable settings and broad coverage, not local “trust me” statements.

Step 4: Monitor and remediate update drift

1. Create an “update compliance” view: devices current, devices stale, agent missing, last check-in time.
2. Define operational thresholds that trigger action (for example, “stale beyond a defined period”); document the threshold you pick as an internal standard, not as a NIST requirement.
3. Route exceptions into ticketing with clear SLAs owned by IT/SecOps.
4. Track recurring causes (VPN off, broken proxy, certificate inspection blocking updates) and fix systemic issues.

Control objective: no long-lived blind spots.

Step 5: Formalize exceptions and compensating controls

Common legitimate exceptions:

• Legacy OS or specialized systems where agents cannot run.
• Operational technology / lab equipment with vendor restrictions.
• Highly restricted enclaves.

For each exception:

1. Record the asset, business justification, and duration.
2. Document compensating controls (application allowlisting, network segmentation, enhanced monitoring, increased scanning cadence where feasible).
3. Obtain risk acceptance approval from the right authority.
4. Revalidate periodically.

Step 6: Tie SI-3(2) to ownership and recurring evidence (assessment readiness)

Assign:

• Control owner: usually Security Operations or Endpoint Engineering.
• Supporting owners: IT Operations, Cloud Platform, Network (for egress/proxy), GRC (for evidence and exceptions).

If you use Daydream for control operations, configure SI-3(2) as a recurring evidence control with automated reminders, a single owner, and a standing evidence checklist so the control does not decay between audits.

Required evidence and artifacts to retain

Keep evidence that proves configuration, coverage, and operation. Recommended artifact set:

1. Control narrative describing how automatic updates are enforced and monitored, including scope and update sources. ¹
2. Configuration evidence:
   • Screenshots/exported settings from the central console showing auto-updates enabled.
   • MDM/Group Policy/config profiles enforcing update settings.
3. Coverage evidence:
   • Asset list or compliance dashboard export showing protected vs. unprotected assets.
   • Agent deployment reports.
4. Operational evidence (recurring):
   • Update compliance report exports.
   • Alert samples for failed updates and associated incident/ticket records.
   • Monthly/quarterly metrics summary (qualitative is fine; avoid unsourced numbers).
5. Exception register with approvals and compensating controls.
6. Change control records for update infrastructure changes (new proxy, new update channel, tool migration).

Common exam/audit questions and hangups

Expect these questions from assessors:

• “Show me where automatic updates are configured and enforced centrally.”
• “Which asset types are in scope, and how do you know coverage is complete?”
• “How do you detect endpoints that haven’t updated recently?”
• “What happens when a device cannot auto-update?”
• “How do you handle restricted networks or offline assets?”
• “Who reviews update failures and how is closure tracked?”

Hangups that cause findings:

• You can show policy, but not console settings.
• You can show console settings, but not a coverage report tied to inventory.
• You can show compliance dashboards, but no tickets or remediation evidence.

Frequent implementation mistakes (and how to avoid them)

1. Mistake: Treating “automatic updates” as a one-time setting.
   Avoid it: add monitoring plus a recurring evidence cadence (dashboard export + ticket samples).

2. Mistake: Ignoring servers and “special” fleets.
   Avoid it: explicitly document how servers update (maintenance windows, internal repository, or exception).

3. Mistake: No defined exception path.
   Avoid it: keep an exception register with approvals and compensating controls; assessors accept constraints if they are governed.

4. Mistake: Split ownership with no one accountable.
   Avoid it: name a single control owner and define what supporting teams must provide (reports, logs, tickets).

5. Mistake: Tool sprawl (multiple unmanaged anti-malware products).
   Avoid it: standardize where possible; where you can’t, map each tool to evidence sources and monitoring.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for SI-3(2). ¹

Risk still matters operationally. Stale detection content increases the likelihood that known malicious code evades controls, and update failures often correlate with other hygiene gaps (unmanaged devices, broken telemetry, misconfigured proxies). Treat SI-3(2) as a leading indicator control: if you cannot prove automatic updates, you may also struggle to prove asset coverage and continuous monitoring across the boundary.

Practical 30/60/90-day execution plan (operator-focused)

Use time phases as a delivery mechanism; tune the timing to your environment and change windows.

First 30 days (get to “defined + visible”)

• Confirm in-scope asset classes and the protection mechanisms you rely on.
• Assign control ownership and publish a one-page SI-3(2) standard (automatic updates + monitoring + exceptions).
• Pull baseline evidence: current console settings and a first update compliance export.
• Stand up an exceptions register and intake path (ticket form + approval workflow).

Days 31–60 (enforce + reduce drift)

• Roll out enforced auto-update policies across major fleets (endpoints, standard servers, cloud workloads).
• Implement monitoring: alerts for stale/out-of-date/agent missing, routed to a queue with ownership.
• Close obvious gaps: devices with broken agents, blocked update channels, mis-scoped groups.
• Produce an “evidence packet” template: what to export monthly, where to store it, who attests.

Days 61–90 (stabilize + audit-proof)

• Expand coverage to edge cases: DMZ, VDI, restricted enclaves, third-party managed devices in scope.
• Validate exception quality: compensating controls described, approvals present, review dates set.
• Run an internal control test: pick a sample of devices and trace end-to-end proof (policy → enforced setting → updated status → monitoring → remediation ticket if stale).
• In Daydream, convert the evidence packet into a recurring control workflow so evidence collection is routine, not a scramble.

Frequently Asked Questions

Does SI-3(2) require automatic updates for every security tool or only anti-malware?

Scope it to “malicious code protection mechanisms,” which typically includes anti-malware/endpoint protection and the content they rely on to detect malicious code. Document your scope decision and keep it consistent with how you actually manage threats. ¹

We have a restricted network with no internet access. Can we still meet the si-3(2): automatic updates requirement?

Yes, if updates are automatic within the enclave using an internal update source (staged packages, internal repository) and endpoints pull updates without manual action. Document the update path and retain evidence of successful updates. ¹

What evidence is “enough” for auditors?

Provide (1) enforced configuration showing auto-updates enabled, (2) a coverage/compliance report tied to your asset inventory, and (3) proof you respond to failures through tickets or incident records. A policy alone rarely closes SI-3(2). ¹

How do we handle endpoints that are often offline (remote workers, infrequent VPN)?

Configure tools to update off-network when possible, then monitor “last seen” and “last update” signals to detect drift. Treat persistent staleness as an operations issue with documented remediation steps. ¹

Can we claim compliance if updates are automatic but we don’t monitor failures?

Expect pushback. Automatic updates are a configuration feature; SI-3(2) assessments commonly probe whether the control operates effectively, which requires visibility into update status and a way to correct failures. ¹

Who should own SI-3(2) in a mature org?

Assign a single owner in Security Operations or Endpoint Engineering, with explicit inputs from IT Ops and Cloud teams. GRC should own the evidence rhythm and exception governance so the control stays testable. ¹

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5