Incidents
Suspicious files in /tmp Jun 16 2007 06:13PM
kladizkov.thehome (kladizkov thehome gmail com) (3 replies)
Re: Suspicious files in /tmp Jun 18 2007 05:12PM
Jamie Riden (jamie riden gmail com)
Re: Suspicious files in /tmp Jun 18 2007 05:08PM
Jamie Riden (jamie riden gmail com)
Re: Suspicious files in /tmp Jun 18 2007 04:47PM
Matt D. Harris (mdh solitox net) (5 replies)
Re: Suspicious files in /tmp Jun 21 2007 11:38AM
Remko Lodder (remko elvandar org) (1 replies)
Hello Matt,

Indeed FreeBSD doesn't respect the cases where a shell script is on a
noexec mounted device; but where /bin/sh is still executable (/bin/sh
/tmp/script for example). From the Manual page this should be clear that
it is not designed as a security measure but to aid other activities; it
is unlikely that we (see the archives for more information, this had been
discussed a couple of times) will change this behaviour (since the design
isn't for
security):

mount(8):

noexec Do not allow execution of any binaries on the mounted
file system. This option is useful for a server that
has
file systems containing binaries for architectures other
than its own. Note: This option was not designed as a
security feature and no guarantee is made that it will
prevent malicious code execution; for example, it is
still possible to execute scripts which reside on a
noexec mounted partition.

Hope this helps aiding you a bit with the information we can deliver.

Regards,
Remko

On Mon, June 18, 2007 6:47 pm, Matt D. Harris wrote:
> They're being executed despite filesystem mount options because the
> script isn't being executed, the perl interpretter is. The script is
> being read and interpretted by the perl interpretter. Interesting - I
> hadn't thought of this before. Some logic to check the underlying
> filesystem of a script before reading it would be a very cool addition
> to perl from a security standpoint. Wouldn't be a big performance hit
> at all just to check once every require, etc as well. It'd need to be
> somewhat platform specific. Anyways, it would be neat for someone to
> bring this up within the Perl community as a possible idea, and maybe
> consider python, ruby, and others as well. Then there're various
> shells... I tested bash and FreeBSD's /bin/sh, and neither of them
> respect the noexec mount flag on FreeBSD either. It seems like this
> should be a relatively easy problem to correct, at least for the most
> common platforms. It's a thought that I'm going to bring up with the
> FreeBSD guys and see what their reaction is. Thanks for bringing this
> up here. Take care, Matt
>
> kladizkov.thehome wrote:
>> Hi,
>>
>> My firewall LFD, pulled out three perl scripts from /tmp. It was found
>> to be executing in my server. I have attached the scripts along with
>> this mail. Is this issue familiar to anyone?
>>
>> How can a script uploaded to /tmp be executed when it has noexec
>> privilege?
>>
>>
>> ------------------------------------------------------------------------

>>
>> ------------------------------------------------------------------------
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>
> ------------------------------------------------------------------------
-
> This list sponsored by: SPI Dynamics
>
> ALERT: .How a Hacker Launches a SQL Injection Attack!.- White Paper
> It's as simple as placing additional SQL commands into a Web Form input
> box
> giving hackers complete access to all your backend systems! Firewalls and
> IDS
> will not stop such attacks because SQL Injections are NOT seen as
> intruders.
> Download this *FREE* white paper from SPI Dynamics for a complete guide to
> protection!
>
> https://download.spidynamics.com/1/ad/sql.asp?Campaign_ID=70160000000Cn8
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>

--
Kind regards,

Remko Lodder ** remko (at) elvandar (dot) org [email concealed]
FreeBSD ** remko (at) FreeBSD (dot) org [email concealed]

/* Quis custodiet ipsos custodes */

------------------------------------------------------------------------
-
This list sponsored by: SPI Dynamics

ALERT: .How a Hacker Launches a SQL Injection Attack!.- White Paper
It's as simple as placing additional SQL commands into a Web Form input box
giving hackers complete access to all your backend systems! Firewalls and IDS
will not stop such attacks because SQL Injections are NOT seen as intruders.
Download this *FREE* white paper from SPI Dynamics for a complete guide to protection!

https://download.spidynamics.com/1/ad/sql.asp?Campaign_ID=70160000000Cn8
E
------------------------------------------------------------------------
--

[ reply ]
Re: Suspicious files in /tmp Jun 21 2007 08:05PM
Cy Schubert (Cy Schubert komquats com)
Re: Suspicious files in /tmp Jun 19 2007 01:33AM
Robin Sheat (robin kallisti net nz) (1 replies)
Re: Suspicious files in /tmp Jun 20 2007 04:47PM
Valdis Kletnieks vt edu (1 replies)
RE: Suspicious files in /tmp Jun 20 2007 11:06PM
Thyago Braga da Silva (tbraga gasecurity com br) (1 replies)
RE: Suspicious files in /tmp Jun 21 2007 05:09PM
kaneda bohater net (1 replies)
Re: Suspicious files in /tmp Jun 22 2007 12:19AM
Eduardo Tongson (propolice gmail com)
Re: Suspicious files in /tmp Jun 19 2007 12:23AM
Rainer Duffner (rainer ultra-secure de)
Re: Suspicious files in /tmp Jun 19 2007 12:17AM
Rainer Duffner (rainer ultra-secure de)
Re: Suspicious files in /tmp Jun 18 2007 09:32PM
Michal Zalewski (lcamtuf dione ids pl) (1 replies)
Re: Suspicious files in /tmp Jun 19 2007 12:37AM
Matt D. Harris (mdh solitox net)


 

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