The Incutio XML-RPC (IXR) Library, as used in WordPress before 3.9.2 and Drupal 6.x before 6.33 and 7.x before 7.31, permits entity declarations without considering recursion during entity expansion, which allows remote attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.