Land rapid7#20428, fixes available payload space in exploits/windows/misc/achat_bof

Fix achat_bof by increasing the available payload space

Author: msutovsky-r7

modules/exploits/windows/misc/achat_bof.rb

@@ -34,7 +34,7 @@ def initialize(info = {})
         },
         'Payload' => {
           'DisableNops' => true,
-          'Space' => 730,
+          'Space' => 1200,
           'BadChars' => "\x00" + (0x80..0xff).to_a.pack("C*"),
           'StackAdjustment' => -3500,
           'EncoderType' => Msf::Encoder::Type::AlphanumUnicodeMixed,