This paper discusses abusing Microsoft SQL Query wildcards to consume
CPU in database servers using only the search field present in most
common web applications.
It can be downloaded from
http://www.portcullis-security.com/uplds/wildcard_attacks.pdf
Majority of the Microsoft SQL Server based web applications are
vulnerable to this attack. Other databases could be vulnerable
depending on how the applications implement search functionalities
although common implementation of the search functionality in SQL
Server back-end applications is vulnerable.
There are real world scenarios and detailed analysis in the paper
which explains and shows the impact of this attack.
Regards,
--
Ferruh Mavituna