Information
This setting configures if guests who use a verification code to access the site or links are required to reauthenticate after a set number of days.
The recommended state is 15 or less.
By increasing the frequency of times guests need to reauthenticate this ensures guest user access to data is not prolonged beyond an acceptable amount of time.
Solution
To remediate using the UI:
- Navigate to SharePoint admin center
https://admin.microsoft.com/sharepoint
- Click to expand Policies > Sharing
- Scroll to and expand More external sharing settings
- Set People who use a verification code must reauthenticate after this many days to 15 or less.
To remediate using PowerShell:
- Connect to SharePoint Online service using Connect-SPOService
- Run the following cmdlet:
Set-SPOTenant -EmailAttestationRequired $true -EmailAttestationReAuthDays 15
Impact:
Guests who use Microsoft 365 in their organization can sign in using their work or school account to access the site or document. After the one-time passcode for verification has been entered for the first time, guests will authenticate with their work or school account and have a guest account created in the host's organization.
Note: If OneDrive and SharePoint integration with Entra ID B2B is enabled as per the CIS Benchmark the one-time-passcode experience will be replaced. Please visit
Secure external sharing in SharePoint - SharePoint in Microsoft 365 | Microsoft Learn
for more information.