This part of the document by Hans Lermen, <email@example.com> on Apr 6, 1997.
These are the hints we give you, when running dosemu on a machine that is (even temporary) connected to the internet or other machines, or that otherwise allows 'foreign' people login to your machine.
Don't set the -s bit, as of dosemu-0.97.10 DOSEMU can run in lowfeature mode without the -s bit set. If you want fullfeatures for some of your users, just use the keyword `nosuidroot' in /etc/dosemu.users to forbid some (or all) users execution of a suid root running dosemu (they may use a non-suid root copy of the binary though) or let them use DOSEMU though "sudo". DOSEMU now drops it root privileges before booting; however there may still be security problems in the initialization code, and by making DOSEMU suid-root you can give users direct access to resources they don't normally have access too, such as selected I/O ports, hardware IRQs and hardware RAM.
If DOSEMU is invoked via "sudo" then it will automatically switch to the user who invoked "sudo". An example /etc/sudoers entry is this:
joeuser hostname=(root) NOPASSWD: /usr/local/bin/dosemu.bin
Use proper file permissions to restrict access to a suid root DOSEMU binary in addition to /etc/dosemu.users `nosuidroot'. ( double security is better ).
NEVER let foreign users execute dosemu under root login !!! (Starting with dosemu-0.66.1.4 this isn't necessary any more, all functionality should also be available when running as user)