Craig Fairchild <[log in to unmask]> wrote:

> P.S. Did you know that being able to send messages like your example
> was at one time a huge security hole on UNIX? It basically allowed very
> clever users to send messages to the terminals of superusers, and those
> messages were then executed as commands from the superuser's session.
> Because of MPE's device security rules (and a few other helpful security
> attributes), we were never in jeapordy from this type of attack.

Many years ago, there was something in Interact related to this.
I think it was something Eugene wrote in the section on questions
and answers.

It showed how the :TELL command strips out all escape sequences
except for display enhancements because of exactly this. (Otherwise,
you could send a msg to SM that was really an MPE command, followed
by the escape sequence to read [and therefore execute] the command.)

There was a bit of a controversy over this article, though, because
it showed how to override this behaviour. (As I recall through this
very fuzzy memory, it required installing a routine into the system SL.)

Bottom line: While we were never in jeopardy from this type of attack,
             we could put ourselves in such a position.

--Glenn Cole
  Software al dente, Inc.
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