lib/rexml/text.rb in the REXML parser in Ruby before 1.9.3-p392 allows remote attackers to cause a denial of service (memory consumption and crash) via crafted text nodes in an XML document, aka an XML Entity Expansion (XEE) attack. Per: http://www.ruby-lang.org/en/news/2013/02/22/rexml-dos-2013-02-22/
"Affected versions
All ruby 1.9 versions prior to ruby 1.9.3 patchlevel 392
All ruby 2.0 versions prior to ruby 2.0.0 patchlevel 0
prior to trunk revision 39384"
Publication date: Wed, 10 Apr 2013 02:55:00 +0000