[EMAIL PROTECTED] said:
> Here comes a small tcl/tk script which will appear under the xdm screen and 
> give the opportunity to halt, reboot or go to a console session (ie kill xdm).

As far as I understand TCL/Tk, those script give everybody with access to the 
screen immediate root access. As far as I can tell, tkmgr doesn't terminate 
when the user logs on. 

If that is indeed the case, the problem is the `send' command of Tk, which 
allows any Tk application to send TCL commands to any other on the same screen. 
I don't know if recent version of TCL/Tk check for more than the absence of a 
xhost list (and therefore enforce xauth authentication). That means a little 
script along the lines of
        #!/usr/bin/whish
        send tkmgr exec {rm -rf /}
can cause quite a bit of inconvenience. 

The minimum thing you could do is to disable the send command in Tk using
        rename send {}
Then it is your decision if you trust this to be secure or not...

                        Cheers,
                                Lukas

-------------------------------------------------------------------------------
   Dr. Lukas Nellen                 | Email: [EMAIL PROTECTED]
   Depto. de Fisica Teorica, IFUNAM |
   Apdo. Postal 20-364              | Tel.:  +52 5 622 5014 ext. 218
   01000 Mexico D.F., MEXICO        | Fax:   +52 5 622 5015


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