(RHSA-2012:1056) Moderate: resteasy security update

RESTEasy provides various frameworks to help you build RESTful web services
and RESTful Java applications.

It was found that RESTEasy was vulnerable to XML External Entity (XXE)
attacks. If a remote attacker submitted a request containing an external
XML entity to a RESTEasy endpoint, the entity would be resolved, allowing
the attacker to read files accessible to the user running the application
server. This flaw affected DOM (Document Object Model) Document and JAXB
(Java Architecture for XML Binding) input. (CVE-2012-0818)

Note: The fix for CVE-2012-0818 is not enabled by default. This update adds
a new configuration option to disable entity expansion in RESTEasy. If
applications on your server expose RESTEasy XML endpoints, a
resteasy.document.expand.entity.references configuration snippet must be
added to their web.xml file to disable entity expansion in RESTEasy. Refer
to Red Hat Bugzilla bug 785631 for details.

Warning: Before applying this update, back up your JBoss Enterprise
Application Platform’s “jboss-as/server/[PROFILE]/deploy/” directory, along
with all other customized configuration files.

All users of JBoss Enterprise Application Platform 5.1.2 as provided from
the Red Hat Customer Portal are advised to install this update.