The (1) Zend_Feed_Rss and (2) Zend_Feed_Atom classes in Zend_Feed in Zend Framework 1.11.x before 1.11.15 and 1.12.x before 1.12.1 allow remote attackers to read arbitrary files, send HTTP requests to intranet servers, and possibly cause a denial of service (CPU and memory consumption) via an XML External Entity (XXE) attack.
http://www.mandriva.com/security/advisories?name=MDVSA-2013:115
http://www.debian.org/security/2012/dsa-2602
http://secunia.com/advisories/51583
http://openwall.com/lists/oss-security/2012/12/20/4