FileRise improper ownership/permission validation allowed cross-tenant file operations

Summary

FileRise is a self-hosted web-based file manager with multi-file upload, editing, and batch operations. Prior to version 1.4.0, a business logic flaw in FileRise’s file/folder handling allows low-privilege users to perform unauthorized operations (view/delete/modify) on files created by other users. The root cause was inferring ownership/visibility from folder names (e.g., a folder named after a username) and missing server-side authorization/ownership checks across file operation endpoints. This amounted to an IDOR pattern: an attacker could operate on resources identified only by predictable names. This issue has been patched in version 1.4.0 and further hardened in version 1.5.0. A workaround for this issue involves restricting non-admin users to read-only or disable delete/rename APIs server-side, avoid creating top-level folders named after other usernames, and adding server-side checks that verify ownership before delete/rename/move.