Re: how an hacker can bypass a chrooted environement ?

["Norbert François" <norbertlike () gmail com>]

Thank you very much for your replies.

But there's smth I still don't understand.
Few months ago I tried to install a jail chroot with "jail"
(http://www.jmcresearch.com/projects/jail/howto.html). In the chrooted
environement I didn't copy programs like "chroot" (itself), "mknod" or
"mount" known to be dangerous... So the only way to bypass this chroot
is to manually upload these tools ? If it is the case, the attacker
has to inject a code opening a socket on the victim's computer, isn't
it ?

Thanks

Norbert

On 5/13/06, Tonnerre Lombard <tonnerre.lombard () sygroup ch> wrote:
> Salut,
>
> On Fri, 2006-05-12 at 11:37, Norbert Fran?ois wrote:
> > I was wondering how an attacker can bypass a chrooted environement. A
> > (common) technique consist in finding a vulnerable program (in the
> > chrooted environnement) and injecting it a shellcode (i.e
> > ../../../../../../../bin/bash for ex.)  by BoF.  But normally, in the
> > chrooted environement, you volontarily add only necessary tools (like
> > ls, cat, less...), and vulnerable softwares are uncommon...
> >
> > So... how do they this "exploit" of bypassing the chroot ?
>
> For example by getting a dir file descriptor from "outside" and
> fchrooting to that one.
>
>                                 Tonnerre
> --
> SyGroup GmbH
> Tonnerre Lombard
>
> Loesungen mit System
> Tel:+41 61 333 80 33    Roeschenzerstrasse 9
> Fax:+41 61 383 14 67    4153 Reinach
> Web:www.sygroup.ch      tonnerre.lombard () sygroup ch
>
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.2.2 (SunOS)
>
> iQIVAwUARGV1Le1mMGan/TnWAQIjOA//Thj6y2a8eDJ65geku0Wih0gXmG99REM1
> I7kSlS9YltO0Lh2KIXB+J7vTM8QuGwf4xQQq2HOfP+XRfXfn4/jcLad8jS+x4Q94
> zRBZgVGaxmsfOPG2iTNhq+EXADQuvxAsAxDIq8W5K33oEc+zs7FBf0A/+VFM8Oc4
> fqT3XwAlmi0LDo8Z0ccydpwsyskqI3ROhFdULn2ttxELYWXuiAP7VFLw9O4qhGHI
> Fq4CNmqcrBjrmpIxdVohDp0dBo28LBYvlJBmbQimfuwut1cqBBW7dERlW+tUibv6
> Ttld+yIruCphh6hr5UcUAqcu88499eAH49oYauOvu3eb6dsZDn82VQkQ2oqTi6C4
> CpqvQUDk50slfoMHUKDDBYZc69dsTNRI2c9hhIqjxZ4kDZ2mA8Y3/VOKVbOYsYN1
> 09IydWc+e/GFezEj9Dfb6gIoC1HWbBX93l6SCgel6zxaqmqO3UFVy8qLAuYlzL+Q
> kD0otPXMwOiXLBb2hhJ37zNQBtIw+ppLfUNvoV/CizDb3YKm8o8u48Hey1kbFMXb
> AzQWm4nDGCxiHIBXgKrOM8/74ZObWBXZiHL0zPeKgErRQzfkOjTYeW+9pfHveDx4
> hMv1GoA2fsqx5vXLQvYYpIKSPOZehMZ4IUzUKfR/Wc8PY4Cuc2Zat6QZUjHUITgt
> lVizK9RfGSw=
> =z6tB
> -----END PGP SIGNATURE-----

------------------------------------------------------------------------------
This List Sponsored by: Cenzic

Concerned about Web Application Security?
Why not go with the #1 solution - Cenzic, the only one to win the Analyst's
Choice Award from eWeek. As attacks through web applications continue to rise,
you need to proactively protect your applications from hackers. Cenzic has the
most comprehensive solutions to meet your application security penetration
testing and vulnerability management needs. You have an option to go with a
managed service (Cenzic ClickToSecure) or an enterprise software
(Cenzic Hailstorm). Download FREE whitepaper on how a managed service can
help you: http://www.cenzic.com/news_events/wpappsec.php
And, now for a limited time we can do a FREE audit for you to confirm your
results from other product. Contact us at request () cenzic com for details.
------------------------------------------------------------------------------