stumbleupon.com, XSS, Cross Site Scripting, CWE-79, CAPEC-86

XSS in stumbleupon.com | Vulnerability Crawler Report

Report generated by CloudScan Vulnerability Crawler at Wed Jan 05 10:01:51 CST 2011.

CWE-79 XSS Report

Loading

1. Cross-site scripting (reflected)

2. Cookie scoped to parent domain

3. Cross-domain Referer leakage

4. Cross-domain script include

5. Cookie without HttpOnly flag set


1. Cross-site scripting (reflected)  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.stumbleupon.com
Path:   /submit

Issue detail

The value of the url request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload b736d"style%3d"x%3aexpression(alert(1))"1ffc17c8275 was submitted in the url parameter. This input was echoed as b736d"style="x:expression(alert(1))"1ffc17c8275 in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response. The PoC attack demonstrated uses a dynamically evaluated expression with a style attribute to introduce arbirary JavaScript into the document. Note that this technique is specific to Internet Explorer, and may not work on other browsers.

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 defenses: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.

Request

GET /submit?title=Curbing+Access+Risk%3a+Role+Based+Access+Governance&url=http%3a%2f%2fblog.aujasnetworks.com%2f2010%2f10%2f13%2fcurbing-access-risk-role-based-access-governance.aspxb736d"style%3d"x%3aexpression(alert(1))"1ffc17c8275 HTTP/1.1
Host: www.stumbleupon.com
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Server: Apache
Set-Cookie: PHPSESSID=thdr0hluc1ci9uboosfqiotkh5; path=/; domain=.stumbleupon.com; HttpOnly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: cmf_i=3676180644d247be9266b82.63927000; expires=Fri, 04-Feb-2011 14:10:49 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_spr=A%2FN; expires=Fri, 04-Feb-2011 14:10:49 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_sp=http%3A%2F%2Fwww.stumbleupon.com%2Fsubmit; expires=Fri, 04-Feb-2011 14:10:49 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: su_c=b4ba2ac9c71548e78458292d543597bd%7C%7C10%7C%7C1294236649%7C7947d20928389989a4da037a120d3b9a; expires=Sat, 02-Jan-2021 14:10:49 GMT; path=/; domain=.stumbleupon.com
Vary: Accept-Encoding
Content-Type: text/html; charset=iso-8859-1
Content-Length: 48016
Date: Wed, 05 Jan 2011 14:10:49 GMT
X-Varnish: 1100795404
Age: 0
Via: 1.1 varnish
Connection: keep-alive


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" xmlns:fb="http://www
...[SNIP]...
<input type="hidden" name="url" value="http://blog.aujasnetworks.com/2010/10/13/curbing-access-risk-role-based-access-governance.aspxb736d"style="x:expression(alert(1))"1ffc17c8275" />
...[SNIP]...
2. Cookie scoped to parent domain  previous  next

Summary

Severity:   Low
Confidence:   Firm
Host:   http://www.stumbleupon.com
Path:   /submit

Issue detail

The following cookies were issued by the application and is scoped to a parent of the issuing domain:The highlighted cookie appears to contain a session token, which may increase the risk associated with this issue. You should review the contents of the cookies to determine their function.

Issue background

A cookie's domain attribute determines which domains can access the cookie. Browsers will automatically submit the cookie in requests to in-scope domains, and those domains will also be able to access the cookie via JavaScript. If a cookie is scoped to a parent domain, then that cookie will be accessible by the parent domain and also by any other subdomains of the parent domain. If the cookie contains sensitive data (such as a session token) then this data may be accessible by less trusted or less secure applications residing at those domains, leading to a security compromise.

Issue remediation

By default, cookies are scoped to the issuing domain and all subdomains. If you remove the explicit domain attribute from your Set-cookie directive, then the cookie will have this default scope, which is safe and appropriate in most situations. If you particularly need a cookie to be accessible by a parent domain, then you should thoroughly review the security of the applications residing on that domain and its subdomains, and confirm that you are willing to trust the people and systems which support those applications.

Request

GET /submit HTTP/1.1
Host: www.stumbleupon.com
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Server: Apache
Set-Cookie: PHPSESSID=q0relcshp10unt4qa8t58nuj12; path=/; domain=.stumbleupon.com; HttpOnly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: cmf_i=8436994294d247ad961d3d8.19597451; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_spr=A%2FN; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_sp=http%3A%2F%2Fwww.stumbleupon.com%2Fsubmit; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: su_c=c50259cbd2e8838b6c5b56aa9311223d%7C%7C10%7C%7C1294236377%7C400ae2ebdc38378b6e1aa016655551de; expires=Sat, 02-Jan-2021 14:06:17 GMT; path=/; domain=.stumbleupon.com
Vary: Accept-Encoding
Content-Type: text/html; charset=iso-8859-1
Content-Length: 6645
Date: Wed, 05 Jan 2011 14:06:17 GMT
X-Varnish: 1603492222
Age: 0
Via: 1.1 varnish
Connection: keep-alive


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" xmlns:fb="http://www
...[SNIP]...
3. Cross-domain Referer leakage  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.stumbleupon.com
Path:   /submit

Issue detail

The page was loaded from a URL containing a query string:The response contains the following links to other domains:

Issue background

When a web browser makes a request for a resource, it typically adds an HTTP header, called the "Referer" header, indicating the URL of the resource from which the request originated. This occurs in numerous situations, for example when a web page loads an image or script, or when a user clicks on a link or submits a form.

If the resource being requested resides on a different domain, then the Referer header is still generally included in the cross-domain request. If the originating URL contains any sensitive information within its query string, such as a session token, then this information will be transmitted to the other domain. If the other domain is not fully trusted by the application, then this may lead to a security compromise.

You should review the contents of the information being transmitted to other domains, and also determine whether those domains are fully trusted by the originating application.

Today's browsers may withhold the Referer header in some situations (for example, when loading a non-HTTPS resource from a page that was loaded over HTTPS, or when a Refresh directive is issued), but this behaviour should not be relied upon to protect the originating URL from disclosure.

Note also that if users can author content within the application then an attacker may be able to inject links referring to a domain they control in order to capture data from URLs used within the application.

Issue remediation

The application should never transmit any sensitive information within the URL query string. In addition to being leaked in the Referer header, such information may be logged in various locations and may be visible on-screen to untrusted parties.

Request

GET /submit?title=Aujas+achieves+Indian+Computer+Emergency+Response+Team%e2%80%99s+(CERT-IN HTTP/1.1
Host: www.stumbleupon.com
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Server: Apache
Set-Cookie: PHPSESSID=ufo7dq43g2vqjk1i1good7ej80; path=/; domain=.stumbleupon.com; HttpOnly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: cmf_i=5893461054d247adf7f2745.73326566; expires=Fri, 04-Feb-2011 14:06:23 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_spr=A%2FN; expires=Fri, 04-Feb-2011 14:06:23 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_sp=http%3A%2F%2Fwww.stumbleupon.com%2Fsubmit; expires=Fri, 04-Feb-2011 14:06:23 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: su_c=0c21d24db07e9f512ef47f48c63a74f7%7C%7C10%7C%7C1294236383%7C7dd5de37803784e61f08bcef14318e09; expires=Sat, 02-Jan-2021 14:06:23 GMT; path=/; domain=.stumbleupon.com
Vary: Accept-Encoding
Content-Type: text/html; charset=iso-8859-1
Content-Length: 6645
Date: Wed, 05 Jan 2011 14:06:23 GMT
X-Varnish: 1603495947
Age: 0
Via: 1.1 varnish
Connection: keep-alive


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" xmlns:fb="http://www
...[SNIP]...
<meta name="description" content="Submit a site to StumbleUpon" />
       
           <link rel="stylesheet" href="http://cdn.stumble-upon.com/css/global_su.css?v=20110103a" type="text/css" media="screen, projection" />
       <!--[if lte IE 6]>
...[SNIP]...
<![endif]-->
       
               
               <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
...[SNIP]...
<![endif]-->
       
       <script type="text/javascript" src="http://cdn.stumble-upon.com/js/plugins_su.js?v=20110103a"></script>
       <link rel="shortcut icon" href="http://cdn.stumble-upon.com/favicon.ico" />
       
       
               <title>
...[SNIP]...
<div id="ff-install-helper" style="display: none;">
               <img id="close-button" src="http://cdn.stumble-upon.com/images/close-button.png" alt="x" />
               <h2>Installing is Easy!<img src="http://cdn.stumble-upon.com/images/s.gif" class="iconArrow24" /></h2>
...[SNIP]...
<div style="padding: 35px 0 200px 320px;" class="clearfix">
                   <img src="http://cdn.stumble-upon.com/i/assets/homePromo1.jpg" height="140" width="278" alt="Discover the best videos from YouTube" class="left" style="margin-left: -300px;"/>
                   <h2 style="padding-top: 15px; margin-bottom: 25px; font-size: 20px;">
...[SNIP]...
<!-- end wrapper -->
       
       <script type="text/javascript" charset="utf-8" src="http://cdn.stumble-upon.com/js/attach_su.js?v=20110103a"></script>
...[SNIP]...
4. Cross-domain script include  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.stumbleupon.com
Path:   /submit

Issue detail

The response dynamically includes the following scripts from other domains:

Issue background

When an application includes a script from an external domain, this script is executed by the browser within the security context of the invoking application. The script can therefore do anything that the application's own scripts can do, such as accessing application data and performing actions within the context of the current user.

If you include a script from an external domain, then you are trusting that domain with the data and functionality of your application, and you are trusting the domain's own security to prevent an attacker from modifying the script to perform malicious actions within your application.

Issue remediation

Scripts should not be included from untrusted domains. If you have a requirement which a third-party script appears to fulfil, then you should ideally copy the contents of that script onto your own domain and include it from there. If that is not possible (e.g. for licensing reasons) then you should consider reimplementing the script's functionality within your own code.

Request

GET /submit HTTP/1.1
Host: www.stumbleupon.com
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Server: Apache
Set-Cookie: PHPSESSID=q0relcshp10unt4qa8t58nuj12; path=/; domain=.stumbleupon.com; HttpOnly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: cmf_i=8436994294d247ad961d3d8.19597451; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_spr=A%2FN; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_sp=http%3A%2F%2Fwww.stumbleupon.com%2Fsubmit; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: su_c=c50259cbd2e8838b6c5b56aa9311223d%7C%7C10%7C%7C1294236377%7C400ae2ebdc38378b6e1aa016655551de; expires=Sat, 02-Jan-2021 14:06:17 GMT; path=/; domain=.stumbleupon.com
Vary: Accept-Encoding
Content-Type: text/html; charset=iso-8859-1
Content-Length: 6645
Date: Wed, 05 Jan 2011 14:06:17 GMT
X-Varnish: 1603492222
Age: 0
Via: 1.1 varnish
Connection: keep-alive


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" xmlns:fb="http://www
...[SNIP]...
<![endif]-->
       
               
               <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
...[SNIP]...
<![endif]-->
       
       <script type="text/javascript" src="http://cdn.stumble-upon.com/js/plugins_su.js?v=20110103a"></script>
...[SNIP]...
<!-- end wrapper -->
       
       <script type="text/javascript" charset="utf-8" src="http://cdn.stumble-upon.com/js/attach_su.js?v=20110103a"></script>
...[SNIP]...
5. Cookie without HttpOnly flag set  previous

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.stumbleupon.com
Path:   /submit

Issue detail

The following cookies were issued by the application and do not have the HttpOnly flag set:The cookies do not appear to contain session tokens, which may reduce the risk associated with this issue. You should review the contents of the cookies to determine their function.

Issue background

If the HttpOnly attribute is set on a cookie, then the cookie's value cannot be read or set by client-side JavaScript. This measure can prevent certain client-side attacks, such as cross-site scripting, from trivially capturing the cookie's value via an injected script.

Issue remediation

There is usually no good reason not to set the HttpOnly flag on all cookies. Unless you specifically require legitimate client-side scripts within your application to read or set a cookie's value, you should set the HttpOnly flag by including this attribute within the relevant Set-cookie directive.

You should be aware that the restrictions imposed by the HttpOnly flag can potentially be circumvented in some circumstances, and that numerous other serious attacks can be delivered by client-side script injection, aside from simple cookie stealing.

Request

GET /submit HTTP/1.1
Host: www.stumbleupon.com
Accept: */*
Accept-Language: en
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)
Connection: close

Response

HTTP/1.1 200 OK
Server: Apache
Set-Cookie: PHPSESSID=q0relcshp10unt4qa8t58nuj12; path=/; domain=.stumbleupon.com; HttpOnly
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: cmf_i=8436994294d247ad961d3d8.19597451; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_spr=A%2FN; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: cmf_sp=http%3A%2F%2Fwww.stumbleupon.com%2Fsubmit; expires=Fri, 04-Feb-2011 14:06:17 GMT; path=/; domain=.stumbleupon.com
Set-Cookie: su_c=c50259cbd2e8838b6c5b56aa9311223d%7C%7C10%7C%7C1294236377%7C400ae2ebdc38378b6e1aa016655551de; expires=Sat, 02-Jan-2021 14:06:17 GMT; path=/; domain=.stumbleupon.com
Vary: Accept-Encoding
Content-Type: text/html; charset=iso-8859-1
Content-Length: 6645
Date: Wed, 05 Jan 2011 14:06:17 GMT
X-Varnish: 1603492222
Age: 0
Via: 1.1 varnish
Connection: keep-alive


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en" xmlns:fb="http://www
...[SNIP]...
Report generated by CloudScan Vulnerability Crawler at Wed Jan 05 10:01:51 CST 2011.