Microsoft .NET Framework 2.0 SP2, 3.5, 3.5 SP1, 3.5.1, 4, and 4.5 does not properly parse a DTD during XML digital-signature validation, which allows remote attackers to cause a denial of service (application crash or hang) via a crafted signed XML document, aka "Entity Expansion Vulnerability."
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.