Wildfly-core: path traversal on wildfly domain controller

A path traversal flaw was found in WildFly's domain mode
implementation. The LocalFileRepository.getFile() and
getConfigurationFile() methods in
wildfly-core/deployment-repository do not validate that the
resolved file path remains within the configured repository or
configuration root directories. A remote attacker who has
obtained the slave host controller secret or compromised a slave
host controller can supply a crafted relative path containing
directory traversal sequences (e.g., ../../etc/passwd) via the
slave-DC wire protocol, causing the Domain Controller to resolve
and serve arbitrary files readable by the DC process. This leads
to unauthorized disclosure of sensitive information such as
configuration files, keystores, and system credentials.