[Dovecot] imapc vs auth-userdb security

[Timo Sirainen]

On Wed, 2011-09-14 at 13:57 +0200, Lutz Preßler wrote:
> On Mi, 14 Sep 2011, Timo Sirainen wrote:
> 
> > On 14.9.2011, at 14.40, Lutz Preßler wrote:
> > 
> > > with imapc settings coming from userdb (individual configuration necessary)
> > > there exists a security problem if access to auth-userdb socket is given
> > > to normal (shell) users:
> > 
> > So don't give it to them? :) Actually this should be pretty much solved with v2.1 defaults. If the auth-userdb socket is 0666 root:root (default now), it requires that the calling process either has root user/group privileges or its uid matches the one returned by userdb, otherwise it won't return any fields.
> I had to change that because of shared mailboxes and usage of %%h.
> Maybe one could return only home if uid does not match?

Well, you could also solve it by making it 0660 with group=dovecot and
then set mail_access_groups=dovecot.