Heads-up: Exim 4.96 RC0 may break your Dovecot LDA delivery

[Aki Tuomi]

You could also just switch to LMTP instead of LDA.

Aki

> On 25/04/2022 16:47 Kirill Miazine <km at krot.org> wrote:
> 
>  
> So my workaround was to create a simple wrapper and call it, instead of
> dovecot-lda:
> 
> $ cat /local/bin/dovecot-lda-wrapper
> #!/bin/sh
> exec /usr/local/libexec/dovecot/dovecot-lda \
>   -d "${LOCAL_PART}@${DOMAIN}" \
>   -a "${LOCAL_PART}${LOCAL_PART_SUFFIX}@${DOMAIN}" \
>   -r "${LOCAL_PART}${LOCAL_PART_SUFFIX}@${DOMAIN}" \
>   -f "${SENDER}"
> 
> Here's how it is called from Exim:
> 
> dovecot_pipe:
>     driver = pipe
>     command = /local/bin/dovecot-lda-wrapper
> #    command = /usr/local/libexec/dovecot/dovecot-lda \
> #                -d $local_part@$domain \
> #                -a $local_part$local_part_suffix@$domain \
> #                -r $local_part$local_part_suffix@$domain \
> #                -r $local_part$local_part_suffix@$domain \
> #                -f $return_path
> 
> • Kirill Miazine [2022-04-25 14:36]:
> > Hi, all
> > 
> > The just released RC0 for Exim 4.96 will break Dovecot LDA delivery as
> > described on https://wiki.dovecot.org/LDA/Exim
> > 
> > Here is the relevant ChangeLog entry:
> > 
> > JH/25 Taint-check exec arguments for transport-initiated external processes.
> >       Previously, tainted values could be used.  This affects "pipe", "lmtp" and
> >       "queryprogram" transport, transport-filter, and ETRN commands.
> >       The ${run} expansion is also affected: in "preexpand" mode no part of
> >       the command line may be tainted, in default mode the executable name
> >       may not be tainted.
> > 
> > As of now I don't have a personal working solution to get untained data.
> > I did try a small hack, but Exim was smart enough to see what I was
> > doing.
> > 
> > -- 
> >     -- Kirill Miazine <km at krot.org>
> 
> -- 
>     -- Kirill Miazine <km at krot.org>