Directory traversal vulnerability in CommuniGate Pro 4.0b4 and possibly earlier versions allows remote attackers to list the contents of the WebUser directory and its parent directory via a (1) .. (dot dot) or (2) . (dot) in a URL.  NOTE: it is not clear whether this issue reveals any more information regarding directory structure than is already available to any CommuniGate Pro user, although there is a possibility that it could be used to infer product version information.