[TUHS] Cool talk on Unix and Sendmail history, by Eric Allman

Rob Pike robpike at gmail.com
Mon Jul 31 07:43:59 AEST 2023

There was also a feature Mike Lesk added that allowed a marked line,
something like

%! command

to cause the command to be executed when the recipient read the mail, for
example to demonstrate a feature of a program or teach the recipient
something. He meant well. Dennis had the closest he ever had to a
conniption, and it was taken out post haste. Meaning well is not enough.


On Mon, Jul 31, 2023 at 4:23 AM Norman Wilson <norman at oclsc.org> wrote:

> Doug McIlroy:
>   This reminds me of how I agonized over Mike Lesk's refusal to remove
>   remote execution from uucp.
> ====
> Uux, the remote-execution mechanism I remember from uucp, had
> rather better utility than the famous Sendmail back-door: it
> was how uucp carried mail, by sending a file to be handed to
> mailer on the remote system.  It was clearly dangerous if
> the remote site accepted any command, but as shipped in V7
> only a short list of remote commands was allowed: mail rmail
> lpr opr fsend fget.  (As uucp was used to carry other things
> like netnews, the list was later extended by individual sites,
> and eventually moved to a file so reconfiguration needn't
> recapitulate compilation).
> Not the safest of mechanisms, but at least in V7 it had a use
> other than Mike fixing your system for you.
> Is there some additional history here?  e.g. was the list of
> permitted commands added after arguments about safety, or
> some magic command that let Mike in removed?  Or was there a
> different remote-execution back door I don't remember and don't
> see in a quick look at uuxqt.c?
> Norman Wilson
> Toronto ON
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