Knowledge Management (XMLForms) in SAP NetWeaver, versions 7.30, 7.31, 7.40 and 7.50 does not sufficiently validate an XML document accepted from an untrusted source.
https://wiki.scn.sap.com/wiki/pages/viewpage.action?pageId=503809832
https://launchpad.support.sap.com/#/notes/2661740