Versions of wget prior to 1.8.2-4 contain a bug that permits a malicious
FTP server to create or overwrite files anywhere on the local file system.
FTP clients must check to see if an FTP server's response to the NLST
command includes any directory information along with the list of filenames
required by the FTP protocol (RFC 959, section 4.1.3).
If the FTP client fails to do so, a malicious FTP server can send filenames
beginning with '/' or containing '/../' which can be used to direct a
vulnerable FTP client to write files (such as .forward, .rhosts, .shosts,
etc.) that can then be used for later attacks against the client machine.