SilverStripe through 4.3.3 has incorrect access control for protected files uploaded via Upload::loadIntoFile(). An attacker may be able to guess a filename in silverstripe/assets via the AssetControlExtension.Referenceshttps://www.silverstripe.org/download/security-releases/https://forum.silverstripe.org/c/releaseshttps://www.silverstripe.org/download/security-releases/CVE-2019-12245
