COMMAND
rexd
PROBLEM
A request for remote command execution contains, among others,
the command to be executed, and a user and group id. By default,
the rexd server believes everything that the client sends it. An
intruder can exploit the service to execute commands as any user
(except perhaps root). The typical rexd server has no protection
against abuse: most implementations have no provision for access
control, nor do they require that the client uses a privileged
network port.