CVE-2008-3790
The REXML module in Ruby 1.8.6 through 1.8.6-p287, 1.8.7 through 1.8.7-p72, and 1.9 allows context-dependent attackers to cause a denial of service (CPU consumption) via an XML document with recursively nested entities, aka an "XML entity explosion."
Date published : 2008-08-27
http://lists.apple.com/archives/security-announce/2009/May/msg00002.html