SharePoint and OneDrive permissions control who can view, edit, and share the files that Teams stores or links to. Because Teams inherits much of its file governance from these services, misconfigured permissions can overexpose documents even when the chat layer appears restricted. Reviewing them regularly is a core security practice.
Expanded Definition
SharePoint and OneDrive permissions are the access rules that determine who can read, edit, download, sync, or reshare files stored in Microsoft 365 collaboration spaces. In practice, these permissions often become the real control plane behind Teams file access, because Teams channels and chats usually surface content that is actually governed by SharePoint or OneDrive.
The key distinction is between collaboration convenience and access assurance. A user may appear to have limited visibility inside Teams while still inheriting a permissive file link, a broad group membership, or an externally shared folder. That is why guidance in the OWASP Non-Human Identity Top 10 and NIST control families such as NIST SP 800-53 Rev. 5 Security and Privacy Controls are so relevant: effective governance depends on knowing which identities, guests, and sharing links can actually reach the data.
Definitions vary across vendors when they describe inheritance, link scopes, and guest access, so the safest interpretation is to treat permissions as a layered model across site, library, folder, file, and link. The most common misapplication is assuming a restricted Teams channel automatically restricts the underlying SharePoint or OneDrive file, which occurs when inherited permissions or anonymous links remain active.
Examples and Use Cases
Implementing SharePoint and OneDrive permissions rigorously often introduces friction for collaboration, requiring organisations to weigh sharing speed against the cost of overexposure and rework.
- A project site uses group-based access for internal staff, while external contractors receive time-bound access to only one document library.
- A OneDrive file shared through a link is converted from “anyone with the link” to a named-recipient permission after a sensitivity review.
- A Teams channel retains restricted chat membership, but the underlying SharePoint site is audited because file inheritance could expose attachments to broader groups.
- An offboarding workflow removes a departing employee from SharePoint groups and revokes shared links that were created for ad hoc collaboration.
- A security team reviews high-risk file shares after reading NHIMG research such as Ultimate Guide to NHIs — Key Challenges and Risks and maps them to Microsoft 365 sharing configurations.
For implementation detail, organisations often align these reviews with the access control guidance in NIST SP 800-53 Rev. 5, especially where privileged file access, external sharing, and periodic recertification intersect.
Why It Matters in NHI Security
SharePoint and OneDrive permissions matter in NHI security because documents frequently contain API keys, tokens, runbooks, architecture diagrams, incident notes, and exported data that can be consumed by both humans and agents. When those permissions are too broad, the resulting exposure is not just an information-sharing issue, it becomes a credential and automation risk. NHIMG research shows that 79% of organisations have experienced secrets leaks, and file stores are a common place where those secrets are accidentally placed or redistributed.
This is also where non-human identities complicate governance. Sync clients, workflows, document ingestion tools, and AI agents may all access files through delegated permissions, making a simple folder share effectively machine-readable across multiple systems. The practical lesson from incidents like the Microsoft SAS Key Breach is that a single exposed file or link can create downstream access far beyond the original intent.
Organisations typically encounter the consequence only after a sensitive file has been discovered externally, at which point SharePoint and OneDrive permissions become operationally unavoidable to address.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 | File sharing and inherited access can expose secrets through over-permissive non-human access paths. |
| NIST CSF 2.0 | PR.AC | Access control governs who can reach collaboration content and shared files. |
| NIST SP 800-53 Rev 5 | AC-2 | Account management supports controlling who may access stored collaboration data. |
Audit file permissions, sharing links, and inherited access for any system that can reach NHI-related data.
