The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.
https://www.redhat.com/archives/fedora-package-announce/2009-June/msg01228.html
https://www.redhat.com/archives/fedora-package-announce/2009-June/msg01201.html
https://www.redhat.com/archives/fedora-package-announce/2009-June/msg01173.html
http://www.ubuntu.com/usn/usn-787-1
http://www.ubuntu.com/usn/usn-786-1
http://www.oracle.com/technetwork/topics/security/cpuapr2013-1899555.html
http://www.openwall.com/lists/oss-security/2009/06/03/4
http://www.debian.org/security/2009/dsa-1812
http://svn.apache.org/viewvc?view=rev&revision=781403
http://security.gentoo.org/glsa/glsa-200907-03.xml
http://marc.info/?l=bugtraq&m=129190899612998&w=2
http://marc.info/?l=apr-dev&m=124396021826125&w=2
http://lists.opensuse.org/opensuse-security-announce/2010-05/msg00001.html
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html