Re: Sendmail 8.7.5

[Chris Fearnley <cjf@netaxs.com>]

'Rob Leslie wrote:'
>
>> I've compiled sendmail 8.7.5 and I've got it running suid-mail!  [I
>> don't see any reason to run it suid-root --- especially given the
>> history of vulnerabilities.]  Then again I've barely tested it.
>
>Interesting. I'd like to test this some.

Having sendmail suid-root, may require a suid-root mail-delivery
agent.  Anyone know if procmail, deliver, and/or mail.local are written
to be secure as suid-root?  procmail is already suid-root in Debian and
Red Hat, so I suspect it is the local mail delivery agent to use if we
opt to make sendmail suid-mail.  Also, since .forward only works if it
is world-readable and your $HOME is world-executable, .procmailrc is
the preferred way to forward mail in a suid-mail sendmail world.  None
of the > 2,000 customers at Net Access complained when we switched to
suid-mail sendmail.  But it is a change from Unix tradition.  I can't
think of any other disadvantages to running sendmail suid-mail,
sgid-mail.

All I did to make sendmail suid-mail was to fix the permissions on
/var/spool/mqueue and /var/spool/mail (I suppose /var/log/sendmail may
need to be setup too).  Since I did it in a hurry, I probably gave too
much permission to these directories.  I'll leave it to a Real guru to
specify the minimal directory permissions for sendmail to run
suid-mail, sgid-mail.

-- 
Christopher J. Fearnley            |    UNIX SIG Leader at PACS
cjf@netaxs.com                     |    (Philadelphia Area Computer Society)
http://www.netaxs.com/~cjf         |    Design Science Revolutionary
ftp://ftp.netaxs.com/people/cjf    |    Explorer in Universe
"Dare to be Naive" -- Bucky Fuller |    Linux Advocate