OPEXUS eCasePortal before version 9.0.45.0 allows an unauthenticated attacker to navigate to the 'Attachments.aspx' endpoint, iterate through predictable values of 'formid', and download or delete all user-uploaded files, or upload new files.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H