9. Denial of Service
Denial of Service (DoS) is a general attack category in which access to network applications or data is denied to intended users. DoS
conditions can be created via many techniques. The most common technique used in database environments is to overload server
resources such as memory and CPU either by flooding them with an excessive number of queries, or with a smaller volume of wellcrafted
queries that consume a disproportionate amount of system resources (e.g., because they lead to recursive look-ups or table
operations). The result in either case is the same; the resource-starved servers become unresponsive and, in some instances, even crash.
The motivations behind DoS attacks are often linked to extortion scams in which a remote attacker will repeatedly crash servers until
the victim meets their demands. Whatever the source, DoS represents a serious threat for many organizations.