小编的话:Kingcope神牛又放干货了。
漏洞在12月1日的Seclist上发布,作者在Debian Lenny (mysql-5.0.51a) 、 OpenSuSE 11.4 (5.1.53-log)上测试成功,代码执行成功后会增加一个MySQL的管理员帐号。
use DBI();
$|=1;
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MySQL privilege elevation Exploit
This exploit adds a new admin user.
By Kingcope
Tested on www.2cto.com
* Debian Lenny (mysql-5.0.51a)
* OpenSuSE 11.4 (5.1.53-log)
How it works:
This exploit makes use of several things:
*The attacker is in possession of a mysql user with 'file' privileges for the target
*So the attacker can create files on the system with this user (owned by user 'mysql')
*So the attacker is able to create TRIGGER files for a mysql table
triggers can be used to trigger an event when a mysql command is executed by the user,
normally triggers are 'attached' to a user and will be executed with this users privilege.
because we can write any contents into the TRG file (the actual trigger file), we write the entry
describing the attached user for the trigger as "root@localhost" what is the default admin user.
* We make use of the stack overrun priorly discovered to flush the server config so the trigger file is recognized.
This step is really important, without crashing the mysql server instance and reconnecting (the server will respawn)
the trigger file would not be recognized.
So what the exploit does is:
* Connect to the MySQL Server
* Create a table named rootme for the trigger
* Create the trigger file in /var/lib/mysql//rootme.TRG
* Crash the MySQL Server to force it to respawn and recognize the trigger file (by triggering the stack overrun)
* INSERT a value into the table so the trigger event gets executed
* The trigger now sets all privileges of the current connecting user in the mysql.user table to enabled.
* Crash the MySQL Server again to force it reload the user configuration
* Create a new mysql user with all privileges set to enabled
* Crash again to reload configuration
* Connect by using the newly created user
* The new connection has ADMIN access now to all databases in mysql
* The user and password hashes in the mysql.user table are dumped for a convinient way to show the exploit succeeded
* As said the user has FULL ACCESS to the database now
Respawning of mysqld is done by mysqld_safe so this is not an issue in any configuration I've seen.
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user created for testing (file privs will minor privileg