The ContentBlockEx method in Workarea/ServerControlWS.asmx in Ektron Content Management System (CMS) 8.5 and 8.7 before 8.7sp2 and 9.0 before sp1 allows remote attackers to read arbitrary files via an external entity declaration in conjunction with an entity reference within an XML document named in the xslt parameter, related to an XML External Entity (XXE) issue.