An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.

Not present

1. The target must receive and process XML transactions.

1. Transaction generator(s)/source(s) and ability to cause arrival of messages at the target with sufficient rapidity to overload target. Larger targets may be able to handle large volumes of requests so the attacker may require significant resources (such as a distributed network) to affect the target. However, the resources required of the attacker would be less than in the case of a simple flooding attack against the same target.

1. Consider the case of attack performed against the createCustomerBillingAccount Web Service for an online store. In this case, the createCustomerBillingAccount Web Service receives a huge number of simultaneous requests, containing nonsense billing account creation information (the small XML messages). The createCustomerBillingAccount Web Services may forward the messages to other Web Services for processing. The application suffers from a high load of requests, potentially leading to a complete loss of availability the involved Web Service.