An attacker utilizes a SOAP message to send the target a crafted DTD which consumes excessive resources when parsed on the end system resulting in resource depletion. DTDs are used to describe how XML documents are processed. Certain malformed DTDs (for example, those with excessive entity expansion as described in CAPEC 197) can cause the XML parsers that process the DTDs to consume excessive resources resulting in resource depletion. In this attack, the XML parser is part of a service that processes SOAP messages.