[comp.soft-sys.andrew] letter-bomb with tm!

janssen@parc.xerox.com (Bill Janssen) (02/28/90)

It is possible to embed a tm object in a message, with an attached
command.  When the message is read, the command will be executed. 
Luckily, it often seems to core-dump.

Bill

nsb@thumper.bellcore.com (Nathaniel Borenstein) (03/01/90)

Excerpts from internet.info-andrew: 27-Feb-90 letter-bomb with tm! Bill
Janssen@parc.xerox. (179)

> It is possible to embed a tm object in a message, with an attached
> command.  When the message is read, the command will be executed. 
> Luckily, it often seems to core-dump.

If this is true -- and I'm not sure how to reproduce it -- it is
sufficiently serious that I think it should be patched, even if tm isn't
a supported program.  This is aTrojan horse you could drive a truck
through!  But how can you attach a command to a tm?

janssen@parc.xerox.com (Bill Janssen) (03/01/90)

tm saves the command it runs in its sub-process.  When you tm_Write, it
saves the command in the file.  When you tm_Read, it reads the command
and calls StartProcess with it.  Fun, eh?

Bill

nsb@THUMPER.BELLCORE.COM (Nathaniel Borenstein) (03/01/90)

Well, that's sort of why I asked the question.  What you described seems
to be the *intended* behavior, but I couldn't get it to happen -- tm's
Write method seems to be broken, and just writes out csh -c -f instead
of what it is supposed to write out.  The only way I could find of
reproducing the tm bug was to put together a data stream by hand. 
Granted that this is still a horrible bug that has to be taken care of
immediately, I was intensely curious as to how you discovered it.  Still
am, for that matter, since I haven't found any way to make the bug
happen without putting together the data stream by hand.

If you're going to give a detailed answer, however, it is probably best
not to post it to the net.... -- Nathaniel