The default configuration of TIBCO Rendezvous (RV) 7.5.2 clients, when -no-multicast is omitted, uses a multicast group as the destination for a network message, which might make it easier for remote attackers to capture message contents by sniffing the network.
http://www.vupen.com/english/advisories/2007/2814
http://www.securitytracker.com/id?1018512
http://archives.neohapsis.com/archives/fulldisclosure/2007-07/0620.html