create chmod helper function

lib/msf/core/post/file.rb

@@ -361,6 +361,18 @@ module Msf::Post::File
     write_file(remote, ::File.read(local))
   end
 
+  #
+  # Sets the executable permissions on a remote file
+  #
+  # @param remote [String] Destination file name on the remote filesystem
+  def chmod_x_file(remote)
+    if session.type == "meterpreter" and session.commands.include?('stdapi_fs_chmod')
+      session.fs.file.chmod(remote, 0700)
+    else
+      cmd_exec("chmod 700 \"#{remote}\"")
+    end
+  end
+
   #
   # Delete remote files
   #

modules/post/multi/manage/upload_exec.rb

@@ -31,13 +31,7 @@ class MetasploitModule < Msf::Post
       # Don't use cmd.exe /c start so we can fetch output
       cmd = rpath
     else
-      begin
-        # client is an alias for session
-        client.fs.file.chmod(rpath, 0700)
-      rescue
-        # Fall back if unimplemented or unavailable
-        cmd_exec("chmod 700 #{rpath}")
-      end
+      chmod_x_file(rpath)
 
       # Handle absolute paths
       cmd = rpath.start_with?('/') ? rpath : "./#{rpath}"