It was found that the ExecutionHandler, PollHandler and SubscriptionHandler classes in JBoss Seam Remoting would unmarshall user-supplied XML, and resolve external entities in this XML. A remote attacker could use this flaw to read files accessible to the user running the application server, and potentially perform other more advanced XXE attacks.
Acknowledgements: Red Hat would like to thank Jon Passki of Coverity SRL for reporting this issue.
This issue has been addressed in following products: Red Hat JBoss Web Framework Kit 2.4.0 Via RHSA-2014:0045 https://rhn.redhat.com/errata/RHSA-2014-0045.html
Upstream patch: https://github.com/seam2/jboss-seam/commit/090aa6252affc978a96c388e3fc2c1c2688d9bb5
Statement: This issue affects Seam 3 remoting, but Seam 3 is not shipped with any Red Hat products, and Seam 3 development has been terminated. This issue is not currently planned to be addressed in a future update to Seam 3. Red Hat JBoss BRMS 5; Red Hat JBoss Enterprise Application Platform 4 and 5; Red Hat JBoss Enterprise Portal Platform 5; Red Hat JBoss Enterprise SOA Platform 4 and 5; and Red Hat JBoss Enterprise Web Platform 5 are now in Phase 3, Extended Life Support, of their respective life cycles. This issue has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat JBoss Middleware and Red Hat JBoss Operations Network Product Update and Support Policy: https://access.redhat.com/support/policy/updates/jboss_notes/