Copyparty is a portable file server. In versions prior to 1.19.8, there was a missing permission-check in the shares feature (the shr global-option). When a share was created for just one file inside a folder, it was possible to access the other files inside that folder by guessing the filenames. It was not possible to descend into subdirectories in this manner; only the sibling files were accessible. This issue did not affect filekeys or dirkeys. Version 1.19.8 fixes the issue.
The product makes files or directories accessible to unauthorized actors, even though they should not be.
Web servers, FTP servers, and similar servers may store a set of files underneath a “root” directory that is accessible to the server’s users. Applications may store sensitive files underneath this root without also using access control to limit which users may request those files, if any. Alternately, an application might package multiple files or directories into an archive file (e.g., ZIP or tar), but the application might not exclude sensitive files that are underneath those directories. In cloud technologies and containers, this weakness might present itself in the form of misconfigured storage accounts that can be read or written by a public or anonymous user.