Improper Restriction of XML External Entity Reference
An Improper XML Parser Configuration issue was discovered in Schneider Electric Wonderware Historian Client 2014 R2 SP1 and prior. An improperly restricted XML parser (with improper restriction of XML external entity reference, or XXE) may allow an attacker to enter malicious input through the application which could cause a denial of service or disclose file contents from a server or connected network.
CWE-611 - Improper Restriction of XML External Entity Reference
Listed 4th in the 'OWASP Top Ten', XML External Entities (XXE) vulnerability allows attackers to provide an XML input that contains an external entity. When the XML is parsed, it can cause data extraction and manipulation, execution of commands, denial-of-service attacks, and server-side request forgery.