ports/51632: luit from x11/XFree86-4-clients is unusable

[Guido Berhoerster]

>Number:         51632
>Category:       ports
>Synopsis:       luit from x11/XFree86-4-clients is unusable
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Wed Apr 30 09:50:10 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Guido Berhoerster
>Release:        FreeBSD 4.8-RELEASE i386
>Organization:
>Environment:
System: FreeBSD hal.privat.lan 4.8-RELEASE FreeBSD 4.8-RELEASE #1: Fri Apr 4 15:35:08 CEST 2003 root at hal.privat.lan:/usr/obj/usr/src/sys/HAL i386


>Description:
luit is a small utility which is part of the XFree86 4.3.0
distribution and is installed by the x11/XFree86-4-clients port.
luit adds locale and ISO 2022 support to Unicode terminals, most
notably xterm.
Unfortunately luit will leave the tty world writable if it is not
setuid root which renders it unusable on a default install of
x11/XFree86-4-clients. This problem is specific to systems without
SVR4 ptys like FreeBSD and documented on the manpage:

----snip----
On systems without SVR4 (``Unix-98'') ptys (notably BSD variants), run-
ning  luit  as an ordinary user will leave the tty world-writable; this
is a security hole, and luit will generate a warning (but still accept
to  run).   A  possible solution is to make luit suid root; luit should
drop privileges sufficiently early to make  this  safe. However,  the
startup code has not been exhaustively audited, and the author takes no
responsibility for any resulting security issues.
----snap----

>How-To-Repeat:

For example try to get a xterm with German localization with

setenv LANG de_DE.ISO8859-15
setenv MM_CHARSET ISO-8859-15
xterm -lc -fa "Luxi Mono"

The resulting xterm prints a warning "Warning: could not change
ownership of tty -- pty is insecure!" and the corresponding tty is
of course world writable.

>Fix:

This could be fixed by installing luit setuid root. If this is
considered too much of a security risk maybe a switch could be added
to the port so that people who need a localized xterm have an
option.


>Release-Note:
>Audit-Trail:
>Unformatted: