In Concrete CMS (formerly concrete 5) below 8.5.7, IDOR Allows Unauthenticated User to Access Restricted Files If Allowed to Add Message to a Conversation.To remediate this, a check was added to verify a user has permissions to view files before attaching the files to a message in "add / edit message”.Concrete CMS security team gave this a CVSS v3.1 score of 4.3 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NCredit for discovery Adrian H