OpenEMR < 8.3.0 Path Traversal Information Disclosure via EDI Archive Restore

OpenEMR before 8.3.0 contains a path traversal vulnerability in the EDI archive restore function. The archrestore_sel POST parameter is passed to the archive restore handler without sanitization for path traversal sequences. The handler checks whether the supplied path exists on the filesystem, and the differing response messages leak whether the target path exists. An authenticated user with EOB Data Entry permissions can probe arbitrary filesystem paths on the server to determine file existence.