In SilverStripe assets 4.0, there is broken access control on files.Referenceshttps://www.silverstripe.org/download/security-releases/https://www.silverstripe.org/blog/tag/releasehttps://forum.silverstripe.org/c/releaseshttps://www.silverstripe.org/download/security-releases/CVE-2019-14273
