The xmlParserHandlePEReference function in parser.c in libxml2 before 2.9.2, as used in Web Listener in Oracle HTTP Server in Oracle Fusion Middleware 11.1.1.7.0, 12.1.2.0, and 12.1.3.0 and other products, loads external parameter entities regardless of whether entity substitution or validation is enabled, which allows remote attackers to cause a denial of service (resource consumption) via a crafted XML document.

Affected: Ubuntu:14.04:LTS: libxml2

Daniel Berrange discovered that libxml2 would incorrectly perform entity substitution even when requested not to. If a user or automated system were tricked into opening a specially crafted document, an attacker could possibly cause resource consumption, resulting in a denial of service.