Multiple directory traversal vulnerabilities in FTPServer.py in pyftpdlib before 0.3.0 allow remote authenticated users to access arbitrary files and directories via vectors involving a symlink in a pathname to a (1) CWD, (2) DELE, (3) STOR, or (4) RETR command.
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.