Businesses rely on outside vendors for everything from accounting and payroll to marketing, cybersecurity, CRM platforms, and IT support. To do their jobs, these vendors often request access to your Microsoft 365 environment or other business systems.
While many of these requests are legitimate, giving third parties unrestricted access without proper oversight can create unnecessary security risks. Recently, more businesses have been receiving requests for third party access, making it more important than ever to understand what you’re approving before clicking ‘Accept.’
Here’s what every business owner and IT decision maker should know.
Why Are Third Party Access Requests Becoming More Common?
Modern business applications are built to integrate with one another. Rather than exchanging files manually, software providers often connect directly to Microsoft 365 through Microsoft’s secure API using Microsoft Entra ID (formerly Azure Active Directory).
For example, a vendor may request access to Microsoft Outlook, OneDrive, SharePoint, Teams, user profile information, calendars, or email mailboxes.
These integrations can improve productivity, automate workflows, and reduce manual work. However, every connection also expands your organization’s attack surface.
We at BlueTeam use a product for MSPs, but anyone can use Microsoft’s Application Management program.
Not Every Request Needs Full Access
One of the biggest mistakes organizations make is approving permission requests without reviewing what the application is actually asking for.
Some applications only need basic profile information, calendar access, or access to a specific SharePoint site. Others may request the ability to read every mailbox, send email on behalf of users, access all files across the organization, maintain offline access, or read your entire directory.
Before approving any request, ask:
• Why does this application need this permission?
• Is there a less privileged option?
• Is this a trusted vendor?
• Has our IT team reviewed the request?
Learn more about least privilege in this blog: What Is Zero Trust Security and Why It Matters for Business | BlueTeam Networks
The Hidden Risks of Third Party Applications
Cybercriminals increasingly target trusted applications because they often bypass traditional security tools. If a malicious or compromised application receives excessive permissions, it may be able to access confidential data, read sensitive emails, download files, create inbox rules, maintain persistent access, or collect information for phishing campaigns.
CISA Supply Chain Security
Best Practices Before Approving Access
Before approving third party applications:
• Verify the vendor.
• Review permissions carefully.
• Limit administrative approvals.
• Review connected applications regularly.
• Enable Multi– Factor Authentication.
Review Enterprise Applications in the Microsoft entra portal.
For an MFA overview go to the Microsoft entra portal here.
Don’t Assume Every Request Is Safe
Many permission requests look official because they use Microsoft’s login screens. While Microsoft provides the platform, it does not automatically verify that every application requesting access is appropriate for your business. If something feels unusual, pause before approving it. A few extra minutes spent reviewing permissions can prevent a costly security incident later.
Build a Process Before the Next Request Arrives
Third party integrations are becoming a normal part of doing business, but they should not become an unmanaged security risk. As a BlueTeam Networks client, we would take care of this for you, but every organization should have a documented process for reviewing, approving, and periodically auditing third party application access. With the right policies and oversight, businesses can safely benefit from cloud integrations while protecting your own as well as any client’s sensitive information.
Stay Secure with BlueTeam Networks
If your employees are receiving requests to grant third party access to Microsoft 365 or other business systems, don’t leave those decisions to chance. Make sure everyone knows the weight of these decisions. BlueTeam Networks can help you review application permissions, implement least privilege access, monitor connected apps, and strengthen your overall Microsoft 365 security posture.
Contact BlueTeam Networks today can safely manage third party access your data secure.
