Change :vuln_test to :os_name for checking OS.

Author: jvennix-r7

modules/exploits/multi/browser/itms_overflow.rb

@@ -21,10 +21,7 @@ class Metasploit3 < Msf::Exploit::Remote
 		:ua_minver  => "4.0.5",
 		:javascript => false,
 		:rank       => NormalRanking,
-		:vuln_test  => # only attempt on OSX (no windows exploit atm)
-			%q{
-				is_vuln = (navigator.userAgent.indexOf("Mac OS X") > -1);
-			}
+		:os_name => OperatingSystems::MAC_OSX
 	})
 
 	def initialize(info = {})