The Java XML parser in Echo before 2.1.1 and 3.x before 3.0.b6 allows remote attackers to read arbitrary files via a request containing an external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue.
https://exchange.xforce.ibmcloud.com/vulnerabilities/49167
http://www.vupen.com/english/advisories/2009/0653
http://www.securityfocus.com/archive/1/501637/100/0/threaded