Login | Register For Free | Help
Search for: (Advanced)

Mailing List Archive: Full Disclosure: Full-Disclosure

0day: Hacking secured CITRIX from outside

 

 

Full Disclosure full-disclosure RSS feed   Index | Next | Previous | View Threaded


pdp.gnucitizen at googlemail

Oct 10, 2007, 8:47 AM

Post #1 of 3 (126 views)
Permalink
0day: Hacking secured CITRIX from outside

http://www.gnucitizen.org/blog/0day-hacking-secured-citrix-from-outside

In the true spirit of GNUCITIZEN half(partial)-disclosure initiative,
we announce that it is possible to gain user access level on
integrated remote CITRIX servers. The bug/feature does not relay on
any client/server vulnerabilities nor client/server misconfiguration
issues. All an attacker needs to do to exploit the weakness is to lure
a victim, part of an integrated network, to a malicious website or
trick them into opening specially crafted ICA files. The attack
results into remote command execution with the access level of the
current user.

The success of the attack relays on the fact that the victim (the
proxy) is part of a CITRIX ring to which he/she can perform pass
through authentication. Once a connection is instantiated, the victim
will unwillingly and transparently login into CITIRIX and perform
several commands specified by the attacker. The attacker can simply
instruct the remote desktop to download files from a remote TFTP
server and execute them locally. Once the attack is performed, the
local connection is terminated and the CITRIX session is cleared. No
user interaction is required!

CAUTION!!! The attack can be used to circumvent/bypass border
firewalls and sneak into private networks. This attack is of type CRSF
(Cross-site Request forgery), although it does not relay on Web bugs.
The attack vector works flawlessly on IE and Firefox (when configured
correctly). It also works with any email client or other types of file
sharing mechanisms. All versions of CITRIX and CITRIX client are
affected. The attack may fail on certain setups.

If you manage to re-discover the type of vulnerability outlined in
this post, we encourage you to keep it private. Give some time for the
folks at CITRIX to react. Currently, I am not aware of any remedy
against the attack. Given CITRIX's popularity among corporations and
big organizations, it is highly recommended to take this warning with
extra caution.

--
pdp (architect) | petko d. petkov
http://www.gnucitizen.org

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/


full-disclosure at hushmail

Oct 10, 2007, 11:05 AM

Post #2 of 3 (111 views)
Permalink
Re: 0day: Hacking secured CITRIX from outside [In reply to]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

SHUT UP VLADIS

On Wed, 10 Oct 2007 11:47:23 -0400 "pdp (architect)"
<pdp.gnucitizen[at]googlemail.com> wrote:
>http://www.gnucitizen.org/blog/0day-hacking-secured-citrix-from-
>outside
>
>In the true spirit of GNUCITIZEN half(partial)-disclosure
>initiative,
>we announce that it is possible to gain user access level on
>integrated remote CITRIX servers. The bug/feature does not relay
>on
>any client/server vulnerabilities nor client/server
>misconfiguration
>issues. All an attacker needs to do to exploit the weakness is to
>lure
>a victim, part of an integrated network, to a malicious website or
>trick them into opening specially crafted ICA files. The attack
>results into remote command execution with the access level of the
>current user.
>
>The success of the attack relays on the fact that the victim (the
>proxy) is part of a CITRIX ring to which he/she can perform pass
>through authentication. Once a connection is instantiated, the
>victim
>will unwillingly and transparently login into CITIRIX and perform
>several commands specified by the attacker. The attacker can
>simply
>instruct the remote desktop to download files from a remote TFTP
>server and execute them locally. Once the attack is performed, the
>local connection is terminated and the CITRIX session is cleared.
>No
>user interaction is required!
>
>CAUTION!!! The attack can be used to circumvent/bypass border
>firewalls and sneak into private networks. This attack is of type
>CRSF
>(Cross-site Request forgery), although it does not relay on Web
>bugs.
>The attack vector works flawlessly on IE and Firefox (when
>configured
>correctly). It also works with any email client or other types of
>file
>sharing mechanisms. All versions of CITRIX and CITRIX client are
>affected. The attack may fail on certain setups.
>
>If you manage to re-discover the type of vulnerability outlined in
>this post, we encourage you to keep it private. Give some time for
>the
>folks at CITRIX to react. Currently, I am not aware of any remedy
>against the attack. Given CITRIX's popularity among corporations
>and
>big organizations, it is highly recommended to take this warning
>with
>extra caution.
>
>--
>pdp (architect) | petko d. petkov
>http://www.gnucitizen.org
>
>_______________________________________________
>Full-Disclosure - We believe in it.
>Charter: http://lists.grok.org.uk/full-disclosure-charter.html
>Hosted and sponsored by Secunia - http://secunia.com/
-----BEGIN PGP SIGNATURE-----
Note: This signature can be verified at https://www.hushtools.com/verify
Charset: UTF8
Version: Hush 2.5

wpwEAQECAAYFAkcNFHoACgkQ+dWaEhErNvQM6AP/ekt3CCtqTxrnVyfYRDz57l9oeJVU
vIcKTIuERgLNLSCGdl21CqgAC2KinIfJaK/70KtV/P62Y5spou5/z4owCKNl8iP6czcp
36cXOwpL4+vHsTTebs4onGTDw7TZnSDf2YA+02kk58NYTjEwiav6MzY+pep64teQCj1h
7Sz/9Kc=
=nCB2
-----END PGP SIGNATURE-----


--
Click here to save up to 50% off a quality steel building.
http://tagline.hushmail.com/fc/Ioyw6h4esimyMWnRSMH37RdqH4pxtUNm1CNPeAwNOoshCui4UuKTva/

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/


marcio.barbado at gmail

Oct 10, 2007, 11:14 AM

Post #3 of 3 (114 views)
Permalink
Re: 0day: Hacking secured CITRIX from outside [In reply to]

On 10/10/07, pdp (architect) <pdp.gnucitizen[at]googlemail.com> wrote:
>
> http://www.gnucitizen.org/blog/0day-hacking-secured-citrix-from-outside
>
> All an attacker needs to do to exploit the weakness is to lure
> a victim


no way!!! really?!


--
Marcio Barbado, Jr.

Full Disclosure full-disclosure RSS feed   Index | Next | Previous | View Threaded
 
 


Interested in having your list archived? Contact lists@gossamer-threads.com
 
  Web Applications & Managed Hosting Powered by Gossamer Threads Inc.