FreeBSD Security Advisory – A malicious HTTP server could cause ftp(1) to execute arbitrary commands. When operating on HTTP URIs, the ftp(1) client follows HTTP redirects, and uses the part of the path after the last ‘/’ from the last resource it accesses as the output filename if ‘-o’ is not specified. If the output file name provided by the server begins with a pipe (‘|’), the output is passed to popen(3), which might be used to execute arbitrary commands on the ftp(1) client machine.