On Thu, Oct 01, 2009 at 12:07:27PM -0400, Daniel J Walsh wrote:
> On 10/01/2009 10:13 AM, Vadym Chepkov wrote:
> > That's the problem, I don't think it was a legitimate call. I scanned every single file in /var/www and I don't see presence on uptime call anywhere. I afraid it was a probe to see if the system can be compromised. I scanned file system for inode 2474106 - it's gone, neither ppid=18807 nor pid=18808 are running, so I am not even sure where else to look.
> >
> > Sincerely yours,
> > Vadym Chepkov
> >
> >
> > --- On Thu, 10/1/09, Daniel J Walsh <dwalsh@xxxxxxxxxx> wrote:
> >
> >> From: Daniel J Walsh <dwalsh@xxxxxxxxxx>
> >> Subject: Re: Strange AVC
> >> To: fedora-selinux-list@xxxxxxxxxx
> >> Date: Thursday, October 1, 2009, 10:06 AM
> >> On 10/01/2009 05:51 AM, Dominick
> >> Grift wrote:
> >>> On Wed, Sep 30, 2009 at 05:21:56PM -0700, Vadym
> >> Chepkov wrote:
> >>>> Hi,
> >>>>
> >>>> I am puzzled, what could have caused this kind of
> >> AVC:
> >>>>
> >>>> type=SYSCALL msg=audit(1254270789.862:74347):
> >> arch=c000003e syscall=2 success=no exit=-13 a0=7f2929f52532
> >> a1=0 a2=d a3=7fff325c4270 items=0 ppid=18807 pid=18808
> >> auid=500 uid=48 gid=48 euid=48 suid=48 fsuid=48 egid=48
> >> sgid=48 fsgid=48 tty=(none) comm="uptime"
> >> exe="/usr/bin/uptime" subj=user_u:system_r:httpd_t:s0
> >> key=(null)
> >>>> type=AVC msg=audit(1254270789.862:74347):
> >> avc: denied { read } for pid=18808
> >> comm="uptime" name="utmp" dev=sda1 ino=2474106
> >> scontext=user_u:system_r:httpd_t:s0
> >> tcontext=system_u:object_r:initrc_var_run_t:s0 tclass=file
> >>>
> >>> Well uptime runs in the httpd_t domain and the httpd
> >> domain (uptime) tried to read /var/run/utmp file.
> >> /var/run/utmp has a object type that is owned by init
> >> scripts for object in /var/run.
> >>>
> >>> you can and should check first to see whether the
> >> types are correct: should "uptime" in this scenario run in
> >> the httpd_t domain (is it called from a webapp (non-cgi)
> >> also is the target object labelled properly (matchpathcon
> >> /var/run/utmp)
> >>>
> >>> Once that is established you can verify whether
> >> httpd_t should be able to access the target type:
> >>>
> >>> sesearch --allow -s httpd_t -t initrc_var_run_t
> >> -c file -p read
> >>>
> >>> With this information you are going to have to make
> >> your security decision.
> >>>
> >>> should you allow it or deny it?
> >>>
> >>> I can tell you that in my configuration /var/run/utmp
> >> also has type initrc_var_run_t. So i guess that is what it
> >> should be.
> >>>
> >>> What i cannot tell you is why and how uptime is
> >> executed in this scenario.
> >>> All i know is that it runs in the httpd_t domain.
> >>>>
> >>>>
> >>>> Sincerely yours,
> >>>> Vadym Chepkov
> >>>>
> >>>> --
> >>>> fedora-selinux-list mailing list
> >>>> fedora-selinux-list@xxxxxxxxxx
> >>>> https://www.redhat.com/mailman/listinfo/fedora-selinux-list
> >>>>
> >>>>
> >>>> --
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> >>>> fedora-selinux-list@xxxxxxxxxx
> >>>> https://www.redhat.com/mailman/listinfo/fedora-selinux-list
> >> You would need to add policy to be able to do this.
> >> Apache being able to read utmp could allow a hacker to
> >> figure out all the user names that have logged onto a
> >> system. It is denied by default.
> >>
> >> You can easily add custom policy using audit2allow.
> >>
> >>
> >> --
> >> fedora-selinux-list mailing list
> >> fedora-selinux-list@xxxxxxxxxx
> >> https://www.redhat.com/mailman/listinfo/fedora-selinux-list
> >>
> Not sure why anyone would be trying to run uptime, but I would watch your logs for other strange behaviour.
maybe some webapp that you may have running "requires" it
>
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