MySQL, when running on Windows, allows remote authenticated users with insert privileges on the mysql.func table to cause a denial of service (server hang) and possibly execute arbitrary code via (1) a request for a non-library file, which causes the Windows LoadLibraryEx function to block, or (2) a request for a function in a library that has the XXX_deinit or XXX_init functions defined but is not tailored for mySQL, such as jpeg1x32.dll and jpeg2x32.dll.
https://exchange.xforce.ibmcloud.com/vulnerabilities/21756
http://www.securitytracker.com/id/1029010
http://www.securityfocus.com/bid/62358
http://www.appsecinc.com/resources/alerts/mysql/2005-003.html
http://secunia.com/advisories/54788