Something I need to remember from time to time.
To allow others to use the repository, create a Unix group for CVS users and then chgrp the repositories root directory to that group. Then set the directory's SGID bit, so that files created in the directory have the same group ID as the directory's group ID. Make the group writeable, readable and executable.
chgrp cvsusers /var/lib/cvsroot
chmod -R g+srwx /var/lib/cvsroot