Re: Root shell vixie cron exploit

1999-09-09 Thread John Kennedy

On Wed, Sep 01, 1999 at 09:08:55PM +0400, Seva Gluschenko wrote:
 man sendmail:
 /-C
 ...skipping...
   -Cfile  Use alternate configuration file.  Sendmail refuses to run
   as root if an alternate configuration file is specified.

 and it does, for sure %-).

 Just tested this on different versions of FreeBSD and had no effects
 except Mail Delivery message:

 The following address has permanent fatal errors:
 -C/tmp/vixie-cf gvs

 So, sendmail _really_ refuses to accept -C key when run as root

  ???  I haven't looked hard at that exploit, but I know sendmail and that
is untrue.

  When an average (non-root) user tries to use a -C in sendmail, sendmail
will drop all its suid privs.  You can (mis-)configure sendmail to do
stupid things like run an arbitrary program is root -- your average user
just can't do that themselves.

  I had assumed that the whole problem with the vixie-cron exploit was
that cron allowed users to invoke sendmail with arbitrary command-line
options *as root*, so dropping SUID status doesn't do any good.
Sendmail doesn't try to protect the root user from themselves.



Re: Root shell vixie cron exploit

1999-09-07 Thread Christos Zoulas

On Sep 1,  9:08pm, [EMAIL PROTECTED] (Seva Gluschenko) wrote:
-- Subject: Re: Root shell vixie cron exploit

| The following address has permanent fatal errors:
| -C/tmp/vixie-cf gvs
|
| So, sendmail _really_ refuses to accept -C key when run as root

You've reached the wrong conclusion. *BSD's cron uses -t and passes
recipients through stdin (which is TRT), instead of kluges to parse
MAILTO and ignore things that start with -.

christos