Safeguard 2.5: Allowlist Authorized Software

Safeguard 2.5: allowlist authorized software requirement is a practical control with a simple goal: reduce risk from unauthorized applications, malware, and “shadow IT” by making software execution default-deny unless approved. In audits and customer due diligence, this control often fails for one of two reasons: teams document an “approved software list” but never enforce it, or they deploy a tool but cannot prove governance (who approves, how exceptions work, and how the allowlist stays current).

For a Compliance Officer, CCO, or GRC lead, the fastest path is to treat allowlisting as a requirement with clear ownership, a defined operating cadence, and a minimum evidence bundle. You will need to coordinate Security Engineering, Endpoint/Platform teams, IT, and application owners. You will also need a decision on scope: endpoints, servers, privileged admin workstations, and/or high-risk segments. Start where the risk is highest and where you can enforce with the least operational disruption, then expand.

This page gives requirement-level implementation guidance aligned to CIS Controls v8 and CIS Controls Navigator v8, with step-by-step actions, artifacts to retain, and the exam questions you should anticipate. ^{1 2}

Regulatory text

Framework requirement (excerpt): “CIS Controls v8 safeguard 2.5 implementation expectation (Allowlist Authorized Software).” ¹
Summary: “Safeguard 2.5: Allowlist Authorized Software.” ²

Operator interpretation: You must (1) define what “authorized software” means in your organization, (2) maintain an authoritative allowlist, and (3) implement enforcement so unauthorized software is blocked or tightly controlled. Policy language alone is insufficient; auditors will look for evidence that the allowlist changes through approvals and that endpoints/servers actually prevent unapproved software from running. ¹

Plain-English interpretation (what the control is asking for)

Allowlisting means you set a rule: software is not allowed to execute unless it is approved. Approval is not informal. It is recorded, reviewed, and tied to a business owner and technical owner. Exceptions exist, but they are time-bound or risk-accepted, and they are visible in reporting.

From a GRC standpoint, the “minimum bar” is:

• A governed list of approved software (name, publisher, version strategy, business purpose, owner).
• A technical control that enforces execution rules on in-scope assets.
• A repeatable operating process: intake, review, approve/deny, deploy, monitor, and periodically revalidate. ¹

Who it applies to (entity + operational context)

Entity types: Enterprises, service organizations, and technology organizations implementing CIS Controls v8. ¹

Operational scope (typical):

• Corporate endpoints (Windows/macOS/Linux).
• Server fleets (especially internet-facing, production, and admin jump hosts).
• Privileged access workstations and CI/CD build agents where software execution risk is concentrated.
• Environments with strong third-party exposure (contractor devices, outsourced IT, managed service tooling) where unauthorized remote tools are common.

Where it is hardest: Engineering-heavy orgs with frequent tooling changes, BYOD, and decentralized admin rights. Your goal is to reduce unknown executable risk without breaking developer velocity. That requires scoping and exceptions that are real, not “everyone is exempt.”

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

1) Establish control ownership and a control card

Create a one-page “control card” that an auditor can read in minutes:

• Objective: prevent execution of unapproved software on in-scope assets.
• Control owner: Security (or GRC) accountable; Endpoint/Platform team responsible.
• Trigger events: new software request, new device enrollment, major OS update, M&A onboarding, incident response.
• Frequency: continuous enforcement; periodic review and reconciliation.
• Exceptions: who can approve, for how long, required compensating controls. This directly addresses a common failure mode: teams cannot show who owns it or how it runs. ¹

2) Define scope and enforcement tiers

Do not start by trying to allowlist everything everywhere. Define tiers:

• Tier A (high assurance): privileged/admin workstations, production servers, jump hosts.
• Tier B (standard): general corporate endpoints.
• Tier C (limited visibility): unmanaged/BYOD where you can only detect, not enforce.

Write the scope statement in operational terms: “All managed Windows endpoints enrolled in EDR/MDM” is testable. “All devices” is not.

3) Build the authoritative approved software catalog

Create an “Approved Software Register” with fields auditors ask for:

• Software name, publisher, and identifier (hash, signer, package ID, or application control rule reference).
• Approved use cases and prohibited use cases (example: “remote access tools only for IT; banned for all others”).
• Requester/business owner, technical owner, data access level, and support model.
• Approval date, last review date, and revalidation trigger (major version changes, vendor acquisition, critical vulnerability). Store it in a controlled system (GRC tool, CMDB, ticketing-backed registry) with audit trails.

4) Integrate approvals into change management and procurement

Make it hard to “sneak in” software:

• Require an approved ticket for installation on managed endpoints.
• Tie procurement intake to software authorization so buying software triggers allowlist review.
• For third-party delivered software (MSP tools, contractor utilities), require the third party to declare tooling and get it approved before deployment.

5) Deploy technical enforcement

Your enforcement mechanism can vary by platform, but your compliance requirement is consistent: in-scope devices block or restrict execution of unapproved software, and you can show it with logs and reports. Common patterns:

• Endpoint application control policies with publisher/signature rules.
• Managed software distribution with local admin restrictions.
• Server allowlisting aligned to golden images and configuration management.

Practical design choice: prefer rules based on trusted publishers/signing where feasible; hash-only rules create constant maintenance and brittle operations.

6) Stand up exception handling that is strict but workable

Define:

• Valid reasons (e.g., emergency support tool during an incident).
• Required approvals (security + system owner).
• Duration and revalidation requirements.
• Compensating controls (extra logging, network segmentation, restricted privileges).
• Revocation: how exceptions are removed and verified.

Exceptions are where audits get messy. If your exception list is longer than your allowlist, you have a governance problem, not a tooling problem.

7) Monitor, review, and remediate (control health checks)

Run recurring control health checks and track remediation to closure:

• Review blocked execution events and trends.
• Identify repeat offenders (teams or devices) and fix root causes.
• Reconcile discovered software inventory against the approved catalog.
• Confirm enforcement coverage on in-scope assets (agent installed, policy applied, reporting working). ¹

Required evidence and artifacts to retain

Keep evidence that shows design, implementation, and operation:

Design artifacts

• Control card/runbook (owner, scope, cadence, exceptions). ¹
• Policy/standard for software authorization and application control.

Implementation artifacts

• Approved Software Register export with audit trail.
• Technical configuration screenshots/exports: application control policies, assigned device groups, server baselines.
• Architecture notes: in-scope asset definitions, enforcement tiers.

Operational artifacts (most important)

• Monthly/quarterly control health check report (coverage, blocks, exceptions, remediation tickets). ¹
• Sample approvals: request ticket, risk review notes, approver identity, deployment record.
• Exception register: open/closed exceptions, approvals, compensating controls, end dates.
• Logs/reports showing policy blocks and policy applied status across the fleet.

Retention tip: define a “minimum evidence bundle per cycle” and store it in a single named location so audits do not turn into scavenger hunts. ¹

Common exam/audit questions and hangups

Auditors and customers tend to ask the same things:

• “Show me the approved software list. Who approves changes, and where is the audit trail?”
• “How do you enforce the allowlist technically on endpoints and servers?”
• “Prove coverage: which assets are in scope, and how do you know policy is applied?”
• “Show examples of blocked software and how you handled it.”
• “How do you manage exceptions, and how do you ensure exceptions expire?”
• “How do you handle software installed by third parties or contractors?”

Hangup to expect: teams present vulnerability scanning or EDR detection as a substitute for allowlisting. Detection helps, but it does not meet the intent of preventing unauthorized execution.

Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails	How to avoid it
“Approved software spreadsheet” with no enforcement	Proves documentation, not control operation	Pair the catalog with application control policies and block logs
Hash-based rules everywhere	Operationally unmaintainable	Prefer publisher/signing and managed package identifiers
Scope is vague	You cannot test or evidence it	Define in-scope assets by enrollment/management state
Exceptions become the norm	Default-allow returns through the side door	Time-box exceptions, require compensating controls, report on exception volume
No recurring review	Allowlist drifts and becomes stale	Schedule control health checks and reconcile inventory to the catalog 1

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this safeguard, so you should treat this as a framework expectation rather than a penalty-cited rule in this write-up.

Operationally, weak allowlisting increases exposure to:

• Malware execution and persistence.
• Unauthorized remote access tools and data exfiltration paths.
• Supply-chain style compromises through “helpful” utilities installed outside governance.
• Audit failures tied to inability to evidence control ownership, cadence, and operation. ¹

Practical 30/60/90-day execution plan

Use this as a deployment sequence. Adjust scope based on your environment, but keep the deliverables.

Days 1–30: Define and prove the control on a small, high-risk scope

• Publish the control card with owner, scope, triggers, and exception rules. ¹
• Pick Tier A scope (admin workstations or a server subset) with strong device management.
• Build the first version of the Approved Software Register and an exception register.
• Implement enforcement in audit mode first if needed for stability, then move to block for a pilot group.
• Define your minimum evidence bundle and where it will live. ¹

Days 31–60: Expand coverage and integrate with business workflows

• Expand enforcement to additional Tier A assets; begin Tier B planning.
• Wire software request/approval into ticketing, procurement, and change management.
• Start monthly control health checks: coverage, top blocked apps, exception aging, remediation status. ¹
• Train IT and app owners on request criteria and timelines.

Days 61–90: Operationalize for audit readiness

• Roll out Tier B endpoints with a clear exception model for engineering or specialized roles.
• Produce an audit-ready evidence packet: catalog, policies, scope definition, sample approvals, block logs, health check outputs.
• Run a tabletop “audit walk-through”: have an operator demonstrate request-to-approval-to-enforcement end-to-end.
• Track remediation items to validated closure with due dates and owners. ¹

Where Daydream fits naturally: Daydream is useful once you’ve defined the control card and evidence bundle, because it can keep the requirement mapped to owners, automate evidence collection reminders, and make control health checks and remediation tracking visible to GRC and operators in one place. ¹

Frequently Asked Questions

Do I need allowlisting on every device to satisfy safeguard 2.5: allowlist authorized software requirement?

CIS expects implementation, but your audit outcome depends on whether you defined a testable scope and can prove enforcement on that scope. Start with managed, high-risk assets and document expansion plans and exception handling. ¹

Is EDR “application blocking” the same as allowlisting?

Sometimes EDR can enforce allowlisting-like rules, but you must show it is configured to block unauthorized execution based on an approved catalog. Auditors will still expect governance artifacts: approvals, exceptions, and review cadence. ¹

How do we handle frequent developer tool changes without breaking productivity?

Use role-based allowlists and a fast approval workflow with clear criteria, plus time-bound exceptions for urgent needs. Keep enforcement strict on privileged/admin workstations even if developer endpoints need more flexibility.

What counts as “authorized software”?

Define it in your standard: approved by a named owner, recorded in the Approved Software Register, and permitted by the enforcement policy for the relevant scope. Tie authorization to business purpose and supportability, not “it’s popular.”

How should we handle software introduced by a third party (MSP tools, contractor utilities)?

Require pre-approval of third-party tooling as part of onboarding and contracting, then enforce via the same allowlist mechanism on the assets they touch. Track these tools explicitly in the register with an accountable internal sponsor.

What evidence do auditors ask for most often?

They ask for proof the control operates: a current approved software catalog with audit trail, enforcement policy assignment to in-scope assets, block logs, and an exception register with approvals and closure records. ¹

Footnotes

1. CIS Controls v8

2. CIS Controls Navigator v8