What evidence do auditors commonly ask for on 9.2 Use DNS Filtering Services?

DNS filtering service configuration and policy; Coverage report for on-network and roaming devices; Block event logs.

What is the most common gap auditors find on 9.2?

Filtering only works on the corporate network

CIS Controls v8.1 · CIS Control 9: Email and Web Browser Protections

`9.2` Use DNS Filtering Services

Use DNS filtering on every end-user device, whether remote or on premises, so that lookups of domains known to be malicious are refused. Implementation Groups: IG1, IG2 and IG3 (part of the IG1 essential cyber hygiene baseline, so every enterprise applies it). Asset type: Devices. Security function: Protect.

Source: CIS Controls v8.1, 9.2. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open CIS Controls v8.1 in the compliance library.

Scope: Implementation Groups: IG1, IG2, IG3. Security function: Protect; asset type: Devices.

Each safeguard shows its Implementation Groups. IG1 is the essential baseline for every enterprise, IG2 adds to it, IG3 is all 153. Version 8.1 adds the Govern security function and asks for more processes to be documented; numbering is unchanged from v8.

artefacts

held by a system

at each review

moderate

to go live

SIEM / log platform

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Block event logs · SIEM / log platform

periodic reviewEvidence produced at each review

Coverage report for on-network and roaming devices · Endpoint management (MDM / EDR)

governing documentDocuments that govern the control

DNS filtering service configuration and policy · Policy repository / GRC workspace

First move

Start with the 1 of 3 artefacts that already live in a system (SIEM / log platform); keep the periodic reviews but log each one as a dated record with a named reviewer.

Common gaps auditors find

Filtering only works on the corporate network
Users can change DNS settings
Category policy too permissive

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

9.1 Ensure Use of Only Fully Supported Browsers and Email Clients · 9.3 Maintain and Enforce Network-Based URL Filters