Add check for Exec-Shield

lib/msf/core/post/linux/kernel.rb

@@ -123,6 +123,18 @@ module Kernel
     raise 'Could not determine ASLR status'
   end
 
+  #
+  # Returns true if Exec-Shield is enabled
+  #
+  # @return [Boolean]
+  #
+  def exec_shield_enabled?
+    exec_shield = cmd_exec('cat /proc/sys/kernel/exec-shield').to_s.strip
+    (exec_shield.eql?('1') || exec_shield.eql?('2'))
+  rescue
+    raise 'Could not determine exec-shield status'
+  end
+
   #
   # Returns true if unprivileged bpf is disabled
   #