Re: The format of password change audit events seems to have changed, Can you confirm the correct record type ?

[Richard Guy Briggs <rgb@redhat.com>]

On 2021-07-08 18:53, warron.french wrote:
> This is an interesting topic.
> 
> Please, can you tell me what audit rule you are using that generates such
> records about root's (*or any other account's) password change?*

This is a built-in to the userspace password management tools and not a
kernel-triggered rule.

You could duplicate the effort by monitoring /etc/shadow for writes if
you are really paranoid about those tools being subverted.

> Sincerely, thank you.
> --------------------------
> Warron French
> 
> On Thu, Jul 8, 2021 at 3:27 PM Steve Grubb <sgrubb@redhat.com> wrote:
> > On Thursday, July 8, 2021 2:19:54 PM EDT Wieprecht, Karen M. wrote:
> > > I've noticed that the messages I'm searching  for in splunk to show root
> > > password changes no longer seem to be in the same format.  Most of our
> > > systems run RHEL7 release 7.9,  and I believe this is a recent change
> > > (I've only noticed this problem in the past 3 months or so?), but we do
> > > have an older 7.5 system, so  I was able to use that to compare against
> > > the 7.5 to  identify what's changed.    I wanted to confirm which record
> > I
> > > should be using now since there are several that get generated now
> > >
> > > The key differences seem to be in the message generated and the keyname
> > > being used for the account being targeted,  but I wanted to confirm that
> > > there isn't some other record I should be looking at to verify that the
> > > root password was changed in the required timeframe since I see several
> > > records being generated from a password change, none of which include
> > > anything as conclusive as the old message that showed the operation as a
> > > "password change".   Here are some fo the fields I'm looking at:
> > >
> > > type=USER_CHAUTHOK
> > > exe=/usr/bin/passwd
> > > [acct targeted for the passwd change]:
> > >             id=root          (old format)
> > >             acct=root      (latest format)
> > > msg
> > >            msg='op=change password  (old format)
> > >            msg='op=PAM:chauthok      (latest format)
> > >
> > > If you can  confirm whether this is the info I should be using now to
> > > confirm password changes, that would be much appreciated.
> >
> > I don't have a RHEL 7.9 machine to compare against. I can set one up in
> > about
> > a week. On 7.6 the event looks like this:
> >
> > type=USER_CHAUTHTOK msg=audit(1625771196.574:162): pid=5113 uid=0
> > auid=1000
> > ses=1 subj=unconfined_u:unconfined_r:passwd_t:s0-s0:c0.c1023
> > msg='op=change
> > password id=1000 exe="/usr/bin/passwd" hostname=rhel7.3 addr=?
> > terminal=pts/0
> > res=success'
> >
> > The problem is that "op= change passwd" has a space in it and will not
> > parse
> > right. I have been trying to correct instances of this so that things
> > parse
> > correctly. Not everyone runs their changes by me for comment. So, its
> > possible that the change was made to fix the space, but usually I suggest
> > people add an underscore.
> >
> > I'll into it more next week.
> >
> > -Steve

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635

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