How to Build a Microsoft 365 Compliance Baseline with CIS Benchmark Microsoft 365
If you’re responsible for Microsoft 365 compliance and security, you’ve probably felt that uncomfortable “are we actually secure?” moment. And honestly, it’s justified. Between stolen laptops, overshared SharePoint sites, over-permissive Teams channels, and risky third‑party apps, your M365 tenant is full of ways data can leak.
That’s where the CIS Benchmark Microsoft 365 comes in. It gives you a concrete, vendor-neutral standard to build a Microsoft 365 compliance baseline and to prepare for a proper M365 security audit.
In this guide, we’ll walk through how to use the CIS Microsoft 365 Foundations Benchmark to:
- Turn vague “we should be more secure” into a structured baseline
- Reduce real‑world risks like weak passwords, oversharing, and insecure apps
- Lay the groundwork for automated compliance in Microsoft 365
We’ll keep it practical and a bit opinionated, based on what actually goes wrong in real tenants—not just theory.
Understand the Shared Responsibility and Why a Baseline Matters
Before you start checking boxes on an m365 compliance checklist, you need the right mindset: Microsoft 365 security is a shared responsibility.
Microsoft is responsible for the underlying cloud infrastructure—datacenters, networks, the platform itself. You are responsible for:
- Who has access to what (identities and permissions)
- How data is shared, stored, and protected
- Which devices and third‑party apps are allowed in
To be blunt: Microsoft gives you the fortress; it’s still your job to lock the doors.
A Microsoft 365 compliance baseline is your agreed “minimum bar” for security and governance. The CIS Benchmark Microsoft 365 is a great way to define that bar because it’s:
- Independent (by the Center for Internet Security, not a vendor brochure)
- Widely recognized by auditors and regulators
- Structured into Level 1 (essential) and Level 2 (enhanced) profiles
Once you choose your baseline and align your tenant to it, you’re no longer guessing. You can show, with evidence, how you’re meeting Microsoft 365 compliance requirements—and where your gaps are.
Typical Risks a Baseline Should Address
The transcript you provided hits on something I see constantly: most breaches don’t start with a super‑advanced zero‑day exploit. They start with really basic stuff:
- Weak or reused passwords (yes, “Password123” and “123456” still happen)
- No multi‑factor authentication (MFA) for admins or even for regular users
- Oversharing of files and sites in SharePoint, OneDrive, and Teams
- Insecure or unnecessary third‑party apps with excessive permissions
- Cached credentials on lost or stolen laptops and mobiles
- Disgruntled or careless insiders with too much access
A CIS benchmark–aligned M365 security assessment forces you to look at these dull but deadly issues systematically rather than reacting after a nasty incident.
Where CIS Benchmark Microsoft 365 Fits In
The CIS Microsoft 365 Foundations Benchmark is essentially a big, opinionated checklist of configurations that:
- Harden identity and access
- Secure email and collaboration
- Lock down devices and endpoints (where integrated)
- Improve logging, auditing, and monitoring
Controls are split across areas like:
- Identity and access management
- Threat protection
- Data protection and sharing
- Logging and monitoring
By using this as the structure of your m365 security audit, you’re not inventing your own standard on the fly. You’re aligning to something auditors already trust, and that you can later map to frameworks like SOC 2, ISO 27001, NIS2, HIPAA, or PCI DSS.
It also makes “automated compliance M365” realistic, because the controls are specific enough that tools can actually measure them.
Step 1: Define Scope and Choose Your CIS Profile
To be honest, this is the step many teams try to skip—and it’s why their audits turn into a mess of spreadsheets.
You need to answer two questions first: what’s in scope and how strict do we need to be?
Decide What Parts of Microsoft 365 Are in Scope
At a minimum, your Microsoft 365 compliance baseline should include:
- Azure AD / Entra ID identities (users, admins, guests)
- Exchange Online (mail flow, anti‑phishing, anti‑spam)
- SharePoint Online & OneDrive (file storage and sharing)
- Teams (chats, channels, file sharing)
- Devices (Intune‑managed devices, if you use it)
For many organizations, that’s already plenty. If you handle particularly sensitive data (financial, health, legal, or government), you might also scope:
- High‑risk departments (finance, legal, R&D)
- Specific high‑value sites or teams storing crown‑jewel data
- Third‑party applications connected via OAuth or Graph API
This is basically your microsoft 365 audit preparation step—being explicit about what you’re actually going to review.
Pick CIS Level 1 vs Level 2 (or a Mix)
The CIS Microsoft 365 Foundations Benchmark defines:
- Level 1 (Essential) – Security settings that are low impact, widely recommended, and suitable for almost all orgs. Think: enforcing MFA, disabling legacy authentication, baseline password protections.
- Level 2 (Enhanced) – Stricter controls that may impact usability but provide stronger protection, especially for high‑risk or regulated environments.
Practical pattern I see work well:
- Use Level 1 as the mandatory baseline for the entire tenant
- Apply Level 2 for:
- Administrators and privileged roles
- Sensitive data locations (HR, finance, M&A, R&D)
- Regulated business units
That gives you a realistic m365 compliance checklist instead of an all‑or‑nothing wish list.
Step 2: Assess Your Current Microsoft 365 Configuration
Once you know your scope and profile, it’s time for a m365 security assessment against the CIS benchmark. You can do this manually, semi‑manually, or fully automated.
The transcript describes a deep, four‑week style Microsoft 365 security audit. You may not need that level of consulting every time, but you do need a structured approach that looks like this.
Review Core Identity and Access Controls
Identity is where attackers start. If they own an account, they own the data.
Key CIS‑aligned checks to include:
- Multi‑factor authentication (MFA)
- Is MFA enforced for admins and highly privileged roles?
- Is MFA rolled out for all users where feasible?
- Are you relying on SMS only, or using authenticator apps / hardware keys?
- Password and sign‑in policies
- Are password complexity and length enforced?
- Are you blocking common and breached passwords?
- Is legacy/basic authentication disabled where possible?
- Admin roles and privilege
- How many Global Admins do you have? (Spoiler: often too many.)
- Are you using Just‑in‑Time access or at least separate admin accounts?
Weak passwords and lack of MFA are still some of the most common findings in an m365 security audit. They’re not exciting, but they’re exactly how real incidents start.
Audit Sharing, Permissions, and Data Exposure
This is where many organizations get a nasty shock.
Microsoft 365 makes collaboration easy—sometimes too easy. CIS benchmark controls push you to:
- Identify anonymous or overly broad sharing on:
- SharePoint sites
- OneDrive folders
- Teams channels and shared files
- Review default sharing policies
- Can users share with anyone with the link?
- Are external users automatically allowed?
- Are guest users reviewed and cleaned up regularly?
- Check sensitive file locations
- Finance sites storing financial or customer data
- HR sites with employee information
- Project/Legal spaces with NDAs, contracts, IP
In real cases, one misconfigured SharePoint library or a “shared with everyone” folder has exposed:
- Full client lists
- Financial records
- HR data
The CIS benchmark gives you a structured way to ask: who can see what, and should they?
Evaluate Third‑Party Apps and Integrations
Every OAuth‑granted app is a potential backdoor. The transcript mentions a classic scenario: a time‑tracking app with full access to emails and files gets compromised, and suddenly the attacker can read everything.
For each app granted tenant or user consent:
- Do you actually use it? If not, revoke it.
- Does it really need the level of access it’s requesting?
- Is the vendor transparent about their own security controls?
CIS controls in this area push you to:
- Regularly review app consent logs
- Limit who can grant consent
- Prefer apps from trusted marketplaces (e.g., Microsoft AppSource)
This is one area where microsoft 365 compliance automation tools add a lot of value, because doing this manually every month is painful and—let’s be honest—rarely sustained.
Step 3: Prioritize Remediation and Close the Biggest Gaps
After a proper assessment, you’ll probably have a long list of gaps. Don’t panic; you’re not expected to fix everything overnight. What matters is prioritization and clear ownership.
Triage Findings by Risk, Impact, and Effort
A sensible approach is to group findings into:
1. Critical / High – Fix ASAP
- Admins without MFA
- Global external sharing enabled by default
- Sensitive sites with “Everyone” or anonymous access
- Insecure legacy authentication still allowed
2. Medium – Plan in the next quarter
- Too many Global Admins
- No formal review of guest users
- Weak or inconsistent device compliance policies
3. Low – Improve over time
- Cosmetic or low‑impact logging gaps
- Non‑sensitive sites with slightly loose defaults
Tie each CIS control gap to:
- A risk description (what could actually go wrong)
- An owner (team or person)
- A due date
This is also where audit‑ready reporting matters. If you’re preparing for SOC 2, ISO 27001, or similar, you’ll want clear evidence of:
- What your baseline is
- Which controls are met
- Which ones have a remediation plan in progress
Address the Human Side: Training and Processes
The transcript makes a strong—and accurate—point: humans are usually the weakest link.
Your Microsoft 365 compliance baseline should include people and process controls, not just technical ones:
- Security awareness training
- How to spot phishing and social engineering
- Why MFA matters and how to use it correctly
- Risks of oversharing links and folders
- Joiner / Mover / Leaver processes
- Removing access promptly when people leave
- Adjusting access when they change roles
- Regular reviews of:
- High‑risk permissions
- Guest access
- Shared mailboxes and admin roles
Without this, you can have the best CIS settings in the world and still be exposed because someone shared the wrong folder with the wrong vendor, or because ex‑employees still have access.
Step 4: Automate and Continuously Monitor Your CIS Baseline
Security isn’t a one‑time project; it’s a moving target. Users change, apps come and go, admins tweak policies, and configuration drift sneaks in.
If you only run a big audit every year, your microsoft 365 compliance baseline is probably out of date for most of that year.
This is where microsoft 365 compliance automation really pays off.
Why You Need Automated M365 Compliance Assessment
Manual assessments:
- Take weeks of admin and security engineer time
- Usually live in spreadsheets that age badly
- Rarely get repeated as often as they should
Automated assessment tools tailored to cis benchmark microsoft 365 can:
- Continuously check your tenant against all 129 CIS Microsoft 365 Foundations controls
- Distinguish between Level 1 and Level 2 non‑compliance
- Run on a schedule (daily, weekly, monthly) so drift is caught quickly
- Produce audit‑ready reports you can hand directly to auditors or leadership
In my experience, this is also how you keep your IT and security teams sane. They can focus on fixing issues instead of hunting for them in five different admin portals.
Example: Using ConfigCobra to Enforce Your CIS Baseline
A concrete example of this kind of automation for Microsoft 365 is ConfigCobra.
ConfigCobra is built specifically for automated compliance M365 scenarios and:
- Continuously checks your Microsoft 365 tenant against the CIS Benchmark Microsoft 365 (all 129 Foundations controls)
- Supports both Level 1 (Essential) and Level 2 (Enhanced) profiles
- Lets you schedule assessments daily, weekly, or monthly
- Detects configuration drift in real time
- Generates PDF audit reports that include findings, evidence, and remediation guidance
- Maps CIS controls to other frameworks like NIS2, ISO/IEC 27001, NIST CSF, HIPAA, PCI DSS, and more
- Supports custom rule sets (e.g., for SOC 2, GDPR, or internal policies)
- Provides role‑based access control so security, IT, and compliance teams can collaborate without stepping on each other
It’s also available via Microsoft AppSource with a free trial and simple per‑user plans, which makes it easier to justify as part of your microsoft 365 audit preparation budget.
This kind of tool basically operationalizes your cis certified microsoft 365 ambition: instead of a heroic one‑off project, you get continuous assurance that your baseline is actually being maintained.
You can learn more and try it here: https://configcobra.com/cis-benchmark
Building a Microsoft 365 compliance baseline with the CIS Benchmark Microsoft 365 isn’t about chasing perfection. It’s about moving from vague comfort (“we think we’re secure”) to evidence‑based confidence (“here’s how we meet Level 1 and where we’re working toward Level 2”).
If you follow the steps in this guide, you’ll be able to:
- Clarify your shared responsibility and scope
- Choose a realistic CIS profile (Level 1 everywhere, Level 2 where it matters most)
- Run a structured m365 security assessment against that baseline
- Prioritize and remediate the highest‑risk findings first
- Bring people, training, and processes into the picture—not just settings
- Move toward microsoft 365 compliance automation so your baseline doesn’t quietly decay
To be honest, the biggest mistake I see isn’t “doing security wrong”; it’s not doing it deliberately. The CIS benchmark gives you the structure. Automation keeps it alive.
If you’re ready to turn your baseline into something measurable and repeatable—and you want audit‑ready reports without living in spreadsheets—take a look at ConfigCobra’s CIS Microsoft 365 automation here: https://configcobra.com/cis-benchmark
Use it alongside the approach in this guide, and you’ll be in a much stronger position for your next Microsoft 365 security audit and for any external compliance review that comes your way.