Forum Discussion
Why are files in SiteCollectionImages in SharePoint Online (O365) anonymous for all tenants?
I just found that files of type images (.jpg, png) or .js files located in anyone's O365 tenant are served with no prompt for authentication. Just wondering if this was done for performance reason in...
I think this is nothing new as the style library has the same issue/solution... everything you put in there is anonymous available
Can this be related to Office 365 CDN? On default configuration at least Style Library and Masterpage Gallery are set as public origins.
https://support.office.com/en-us/article/Use-the-Office-365-content-delivery-network-with-SharePoint-Online-bebb285f-1d54-4f79-90a5-94985afc6af8
You can check public origins with "Get-SPOTenantCdnOrigins -CdnType Public"
https://technet.microsoft.com/en-us/library/mt790770.aspx,
