Directory traversal vulnerability in FTPx Corp FTP Explorer 10.5.19.1 for Windows, and probably earlier versions, allows remote FTP servers to write arbitrary files via a "..\" (dot dot backslash) in a filename.
Improper Limitation of a Pathname to a Restricted Directory The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.