SabreDAV before 1.7.11, as used in ownCloud Server before 5.0.15 and 6.0.x before 6.0.2, allows remote attackers to read arbitrary files, cause a denial of service, or possibly have other impact via an XML External Entity (XXE) attack.
https://github.com/fruux/sabre-dav/releases/tag/1.7.11
http://owncloud.org/about/security/advisories/oC-SA-2014-006/