Hello everyone, I was reading SQL WILDCARD DOS 
http://www.portcullis-security.com/uplds/wildcard_attacks.pdf and I was 
wondering if Nessus can detect if SQL is vulnerabile to the Wildcard DOS that 
is outlined in the above 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.

TESTING FOR SQL WILDCARD DOS 
http://www.portcullis-security.com/uplds/wildcard_attacks.pdf

Testing is quite simple; just craft a query which will not return a result4 and 
includes several wildcards. Send this data through the search feature of the 
application. If the application takes more time than a usual search, it is 
vulnerable. More details about crafting a wildcard attack can be found under 
“Crafting Search Keywords” below.

During testing I used the “Web Application Stress Tool5” to carry out attacks. 
Any similar tool can be employed for this purpose.

REAL WORLD IMPACT 
It has been said that this issue affects almost all SQL Server backend systems 
with a search feature.

PROTECTION 
It is important to realise that wildcard attacks are not the result of a flaw 
at the database level, it is the application that is at fault. The application 
should be responsible for filtering wildcards. The subsections below detail 
some mitigation strategies which can be implemented at the application level to 
protect against wildcard attacks.

Take Care and Have Fun --John
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