The Call Policy Configuration page in Cisco TelePresence Video Communication Server (VCS) Expressway X8.5.3 improperly validates external DTDs, which allows remote authenticated users to read arbitrary files or cause a denial of service via a crafted XML document, aka Bug ID CSCuv31853.
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.