5 Common Security Gaps We Find During IT Security Reviews

Microsoft 365 has become an essential part of day-to-day business, helping teams communicate, collaborate and manage their work from almost anywhere. But while it offers a range of built-in security features, simply having Microsoft 365 in place doesn’t necessarily mean your business is fully protected.

Over time, changes to user accounts, permissions, devices and working practices can leave gaps in your security setup. Some are easy to overlook, particularly when everything appears to be working as it should.

An IT Security Review can help identify these weaknesses, highlight areas for improvement and give you a clearer picture of how well your Microsoft 365 environment is protected.

Here are five common security gaps worth looking out for.

1. Multi-Factor Authentication Isn’t Fully Enforced

Passwords alone are no longer enough to protect business accounts. Even strong passwords can be compromised through phishing attacks, data breaches or password reuse.

Multi-Factor Authentication (MFA) adds another layer of protection by requiring users to verify their identity through an additional method, such as an authenticator app.

However, one common issue is that MFA hasn’t been consistently applied across every account. Some users may have it enabled while others, including accounts with higher levels of access, may have weaker protection.

Why it matters:

If an attacker obtains a user’s password, they could potentially gain access to emails, files, business information and other Microsoft 365 services.

What to do:

• Ensure MFA is enforced for all users.
• Pay particular attention to administrator and privileged accounts.
• Consider using Microsoft Entra Conditional Access policies to strengthen sign-in requirements.
• Review authentication methods and remove outdated or insecure options where appropriate.

2. Too Many Users Have Unnecessary Permissions

Not everyone in your business needs access to everything. However, user permissions can gradually become outdated as employees change roles, responsibilities evolve or new accounts are created.

This can result in users retaining access to files, shared folders, applications or administrative settings they no longer need.

Administrator accounts are particularly important to review. Giving too many people elevated permissions increases the potential impact if an account is compromised.

Why it matters:

Unnecessary permissions increase the amount of business information that could be exposed if a user account is compromised. They can also make it harder to control who has access to sensitive information.

What to do:

• Regularly review user accounts and access permissions.
• Remove access that is no longer required.
• Limit administrator privileges to authorised personnel.
• Apply the principle of least privilege, giving users only the access they need to do their jobs.

3. Email Security Settings Aren’t Properly Configured

Email remains one of the most common ways cybercriminals target businesses. Phishing emails, malicious attachments and impersonation attempts can all put business accounts and sensitive information at risk.

Microsoft 365 includes several tools designed to help protect against these threats, including Exchange Online Protection and Microsoft Defender for Office 365. However, having access to these features doesn’t automatically mean they are configured correctly or being used to their full potential.

Some businesses may also have gaps in their email authentication settings, particularly SPF, DKIM and DMARC.

Why it matters:

Poorly configured email security can make it easier for malicious emails to reach employees, or for attackers to impersonate your business and send fraudulent messages to customers and suppliers.

What to do:

• Review Microsoft 365 email protection and anti-phishing policies.
• Check that SPF, DKIM and DMARC records are correctly configured.
• Consider additional protection against malicious links and attachments.
• Make sure employees know how to recognise and report suspicious emails.

4. Devices Aren’t Being Properly Managed or Protected

With more employees working remotely, accessing business information from different locations and devices has become part of everyday working life.

But how much visibility does your business have over the devices connecting to its Microsoft 365 environment?

Without appropriate device management, businesses may struggle to ensure laptops, desktops and mobile devices are kept up to date, protected and configured securely.

Personal devices can also introduce additional risks if they are allowed to access company information without suitable security requirements.

Why it matters:

An unsecured or outdated device can provide another route for attackers to access business systems and information. Lost or stolen devices can also expose sensitive company data.

What to do:

• Keep operating systems and applications up to date.
• Ensure devices have suitable antivirus and endpoint protection.
• Consider Microsoft Intune for managing and securing business devices.
• Apply appropriate access policies to devices connecting to company resources.
• Review how company information is accessed and stored on personal devices.

5. Backups and Recovery Plans Aren’t Being Reviewed

Many businesses assume their data is protected simply because they use Microsoft 365. While Microsoft provides infrastructure resilience and certain retention and recovery capabilities, these should not be confused with a complete independent backup strategy.

Accidental deletion, malicious activity, ransomware and other incidents can all result in important business information being lost or becoming inaccessible.

Without a suitable backup and recovery plan, getting systems and data back to normal could take considerably longer than expected.

Why it matters:

Losing access to emails, documents, customer information or other business-critical data can disrupt operations, affect productivity and potentially result in financial losses.

What to do:

• Review your existing Microsoft 365 backup arrangements.
• Ensure important business data is backed up independently where appropriate.
• Check that backups are running successfully.
• Test recovery processes regularly.
• Make sure you understand how quickly your business could restore important information following an incident.

Is Your Microsoft 365 Environment as Secure as You Think?

Security isn’t something you can simply set up once and forget about. As your business grows, employees change roles and new technologies are introduced, your IT environment needs regular attention to ensure it remains secure.

An IT Security Review helps you understand where your current setup stands, identify potential weaknesses and prioritise improvements based on your business requirements.

At SMS, we help businesses review their Microsoft 365 environments, assess existing security configurations and identify opportunities to strengthen protection.

Whether it’s reviewing user permissions, checking authentication settings or looking at your wider security arrangements, understanding where potential gaps exist is an important first step.

Want to find out how secure your Microsoft 365 environment really is?

Microsoft 365 Security Review £250 + £10/user (ex VAT). Book a security review with our expert team today and find out where your business may have security gaps and how to strengthen your protection. Book Your Review