Please port CXF-5810, which is the root cause of the issue, to JBoss WS.

When a web service has a WS-Security Signature policy in its WSDL and throws a SOAP Fault, it returns an empty HTTP response that has zero-length of content to client instead of the SOAP Fault.

This happens only with Signature policy and doesn't happen with any other WS-Security policies like UsernameToken, or without WS-Security.