You are trying to scan a SharePoint site, but you get an error stating "User scan-user does not have permissions to scan http://example-sharepoint-site/",
When you connect to the same SharePoint site using a browser, you are able to do so without any problems.
Insufficient permissions on the root of the discover target.
When running a discover scan, the scan starts from the 'root' level URL that you have entered as the target.
At this level, 'browse directories' permission is needed.
This allows the user to retrieve a listing of all folders and items present in the site.
The least privileged permission level with the 'browse directories' permission is the 'contribute' permission level.