Use snake_case

modules/exploits/linux/http/efw_chpasswd_exec.rb

@@ -142,7 +142,7 @@ class Metasploit4 < Msf::Exploit::Remote
     data = post_data.to_s
     boundary = post_data.bound
 
-    refererUrl =
+    referer_url =
       "https://#{datastore['RHOST']}:#{datastore['RPORT']}" +
       "#{datastore['TARGETURI']}"
 
@@ -153,7 +153,7 @@ class Metasploit4 < Msf::Exploit::Remote
         'uri' => datastore['TARGETURI'],
         'ctype' => "multipart/form-data; boundary=#{boundary}",
         'headers' => {
-          'Referer' => refererUrl
+          'Referer' => referer_url
         },
         'data' => data
       })