Kiteworks Totemomail 7.x and 8.x before 8.3.0 allows /responsiveUI/EnvelopeOpenServlet messageId directory traversal for unauthenticated file read and delete operations (with displayLoginChunkedImages) and write operations (with storeLoginChunkedImages).
The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize "/dir/../filename" sequences that can resolve to a location that is outside of that directory.