Is GNU Screen suid root the only way to do multi-user mode?

Question

I am running Ubuntu 11.10 and the GNU screen version is "4.00.03jw4", and I am trying to use multi-user mode.

The following process works for me:

as user "first_user" > sudo chmod u+s /usr/bin/screen > sudo chmod 755 /var/run/screen and only after that can you do > screen -S session_name or if you've already created a screen session, > screen -r session_name and inside of screen: >^A:multiuser on >^A:acladd second_user "#?" and if you want second_user to only be an observer >^A:aclchg second_user -w "#?" now you can, as user "second_user", do > screen -x first_user/ to connect when you're all done, do > sudo chmod us /usr/bin/screen > sudo chmod 775 /var/run/screen because running screen suid root is a security risk 

It is depressing. I searched hard, but I cannot find a better way. There is one?

Answer 1

You're right. This is the only way to launch a multi-user screen.

However, if your mailbox is not exposed very much, I do not think that leaving the suid bit is a huge security risk.

-Ben