How to Audit External File Sharing and Guest Access

Why External Sharing Is Different From Cloud Storage Audit

A cloud storage permission audit focuses on one platform at a time: Google Drive settings, OneDrive sharing, Dropbox link reports. An external sharing audit asks a broader question: which external parties, across all our systems, currently hold access to any of our files?

The broader question matters because external access accumulates in multiple places. A single contractor engagement might produce access on Google Drive (shared folder), DocSend or SendNow (sent documents), Dropbox (project files), the client's Slack guest workspace, and whatever specialist tool the contractor needed. Closing one of these without the others creates a false sense of security.

The second difference is the process dimension. Cloud storage audits are about configuration state. External sharing audits are about configuration state plus whether your organization's onboarding, offboarding, and engagement-closeout processes actually catch external sharing.

Scope Definition

Before the audit starts, define scope explicitly. For a typical first audit, scope should include: every platform used for file sharing with external parties, every active external guest and client contact, every link active in the past 12 months. The time window matters because platform logs may have retention limits — if your audit log covers only 90 days, extend the scope to also check the raw sharing lists (which do not age out).

For recurring audits, scope narrows to: changes since the last audit, new engagements started since the last audit, and remediation items from the previous audit. This keeps subsequent audits lighter without losing the discipline.

Inventorying External Shares Across Platforms

List every platform in use. For each, generate the appropriate report. Common platforms and where to find the data:

Identifying Sensitive Content

Not every external share needs the same scrutiny. Flag folders that match sensitive categories: financial data, customer records, legal documents, HR records, intellectual property. If your organization has a data classification scheme, use it; if not, a simple sensitivity tag applied to folder names (CONFIDENTIAL, INTERNAL, RESTRICTED) is enough to drive triage.

External shares inside sensitive folders go to the top of the review list. Shares of routine marketing collateral stay lower priority. The point is to focus attention where exposure matters, not to review every share with equal weight.

Public and Anonymous Links

Any link that works without authentication for anyone who holds the URL is treated as public. Across platforms, these are the highest-risk shares. For every public link found, decide: is this file genuinely public (marketing content, public policy documents), or did someone intend restricted access and configure it wrong?

For files that should be public, document the decision — this prevents re-flagging in the next audit. For files that should not be public, revoke immediately and investigate how the setting was created. Platform settings that default to "anyone with the link" are often the root cause; changing the organization default to domain-restricted is the structural fix.

External Guests and Groups

Export the full list of external guest accounts across every platform. For each guest, document: who they are, which engagement they were added for, who sponsored their access, and whether that engagement is still active. If the engagement is closed, the guest should be removed.

Groups require a specific review because a single group can mask dozens of individual accounts. Review the current membership of every group that holds access to sensitive content. For files where you need maximum visibility, replace group access with named individual permissions. See the permissions explainer for the tradeoff.

The Contractor and Vendor Lifecycle

Contractors are the single largest source of stale access in most organizations. The pattern repeats: a contractor is added to multiple file-sharing surfaces during onboarding, the engagement runs for 3-12 months, and when it ends only the HR offboarding happens. The file-sharing access remains active.

The fix is a documented contractor engagement checklist that includes file-sharing offboarding alongside the usual payroll and equipment steps. At engagement close: remove from each platform's guest list, revoke any specific shared folders, delete any specialist platform links, verify in the audit log that no further access attempts succeed. The checklist takes 15 minutes if someone runs it; without it, access persists indefinitely.

Departed Users and Dormant Accounts

Employees leave. If the organization uses SSO, their central account is disabled during offboarding and connected platforms lose access. If any file-sharing platform is not connected to SSO, the departed employee's separate account may remain active. Audit for accounts that have not logged in for 90 days — this surfaces both departed employees and inactive external users.

For specialist platforms (DocSend, SendNow, Papermark, etc.) that are often added for specific use cases, verify the user list against your current HR roster. Any account that does not correspond to a current employee should be investigated.

Remediation Actions

For each finding, the remediation is one of three actions: revoke access, tighten the control (add expiry, add password, scope down permissions), or document the decision to retain the access as-is. Documentation matters for the retain cases — otherwise the same finding appears again in the next audit and consumes review time.

Track remediation to completion rather than treating the discovery as the end state. A finding is only resolved when the action is confirmed to have taken effect — see the next step.

Retesting After Remediation

For each revocation, verify it worked. Attempt to open the revoked link; the attempt should fail. Check the subsequent audit log for the revoked user; no successful access should appear. For permission tightening, verify the new settings in the sharing dialog.

Retest closes the loop and catches partial remediation — a common issue when files sit in shared folders whose inherited permissions were not addressed.

Reusable Audit Worksheet

A spreadsheet with these columns, one row per finding, covers the operational need. Keep each quarter's worksheet so trends become visible over time.

Pass/fail standard: at the end of the audit cycle, every finding has a status (resolved, documented as retained, or scheduled with a specific date). Open findings without an action owner constitute a failure of the audit itself.

Scheduling Recurring Reviews

Put the next audit on the calendar before closing the current one. For most teams, quarterly works; for high-churn consulting or agency environments, monthly is better. The best audits are the ones that happen on schedule rather than the ones that happen after an incident.

For additional context on the organizational side of file-sharing policy, see file sharing for remote teams. For the full framework covering all external sharing methods and controls, see the secure file sharing for business guide.

Frequently Asked Questions