Current Research | Full Disclosure | As of March 14, 2011

XSS, Cookie, Cross Site Scripting, www.groupon.com, 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 Tue Mar 01 11:32:41 CST 2011.

The DORK Report

1. Cross-site scripting (reflected)

2. Cookie scoped to parent domain

2.1. http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1

2.2. http://www.groupon.com/user_demographics/demographic_form_banner.html

3. Cross-domain Referer leakage

4. Cross-domain script include

5. Cookie without HttpOnly flag set

5.1. http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1

5.2. http://www.groupon.com/user_demographics/demographic_form_banner.html

6. Content type incorrectly stated

1. Cross-site scripting (reflected) next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/user_demographics/demographic_form_banner.html

Issue detail

The value of the subscriber_email cookie is copied into the HTML document as plain text between tags. The payload 16b2a<script>alert(1)</script>4eec7245226 was submitted in the subscriber_email cookie. 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.

Because the user data that is copied into the response is submitted within a cookie, the application's behaviour is not trivial to exploit in an attack against another user. Typically, you will need to find a means of setting an arbitrary cookie value in the victim's browser in order to exploit the vulnerability. This limitation considerably mitigates the impact of the vulnerability.

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.

Request

GET /user_demographics/demographic_form_banner.html?addx=test@fastdial.net&_=1298999611622 HTTP/1.1
Host: www.groupon.com
Proxy-Connection: keep-alive
Referer: http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301
x-requested-with: XMLHttpRequest
content-type: application/x-www-form-urlencoded
accept: text/javascript, text/html, application/xml, text/xml, */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.107 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: b=2148c93a-394a-11e0-aca6-005056951763; visited=true; _chartbeat2=sq6k5rzuuoqiwvy6; subscriber_email=test%40fastdial.net16b2a<script>alert(1)</script>4eec7245226; _tpaid=newsletter; adchemy_id=; _tpmed=email; division=san-jose; s=29108ae4-4427-11e0-ae71-005056952866; email=test%40fastdial.net; _thepoint=c34d720c801b2b00e49f006c1240e874; __utmz=44473723.1298999612.2.5.utmcsr=newsletter|utmccn=(not%20set)|utmcmd=email|utmcct=san-jose_feed; __utma=44473723.1103413385.1297805149.1297805149.1298999612.2; __utmc=44473723; __utmv=44473723.|2=Exp-default=1250235324%2F2=1,; __utmb=44473723.1.10.1298999612

Response

HTTP/1.1 200 OK
Server: nginx/0.7.65
Date: Tue, 01 Mar 2011 17:29:41 GMT
Content-Type: text/html; charset=utf-8
Set-Cookie: subscriber_email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:29:41 GMT
Set-Cookie: adchemy_id=; path=/
Set-Cookie: division=san-jose; path=/; expires=Fri, 01-Apr-2011 17:29:41 GMT
Set-Cookie: email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:29:41 GMT
Set-Cookie: mobile=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _thepoint=c34d720c801b2b00e49f006c1240e874; domain=.groupon.com; path=/; expires=Wed, 02 Mar 2011 17:29:41 GMT; HttpOnly
Status: 200
ETag: "8ef21b84a48ea392c576af786a46e9f2"
X-Runtime: 44
Cache-Control: private, max-age=0, must-revalidate
Connection: close

<div class='clearfix' id='above_main'>
<div class='demographic_banner clearfix' id='demographic_collection_form'>
<form action="/user_demographics/update_with_optional_subscription" class="new_u
...[SNIP]...
<div title='test@fastdial.net16b2a<script>alert(1)</script>4eec7245226'>
test@fastdial.net16b2a<script>alert(1)</script>4eec7245226
</div>
...[SNIP]...

2. Cookie scoped to parent domain previous next
There are 2 instances of this issue:

/san-jose/deals/pure-barre-los-gatos-1
/user_demographics/demographic_form_banner.html

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.

2.1. http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1 next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/san-jose/deals/pure-barre-los-gatos-1

Issue detail

The following cookies were issued by the application and is scoped to a parent of the issuing domain:

_tpaid=newsletter; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
_tpmed=email; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
_thepoint=c34d720c801b2b00e49f006c1240e874; domain=.groupon.com; path=/; expires=Wed, 02 Mar 2011 17:13:00 GMT; HttpOnly

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.

Request

GET /san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301 HTTP/1.1
Host: www.groupon.com
Proxy-Connection: keep-alive
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.107 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: b=2148c93a-394a-11e0-aca6-005056951763; subscriber_email=test%40fastdial.net; division=san-jose; email=test%40fastdial.net; visited=true; __utmz=44473723.1297805174.1.4.utmcsr=newsletter|utmccn=laser-and-cosmetic-center|utmcmd=email; __utma=44473723.1103413385.1297805149.1297805149.1297805149.1; __utmv=44473723.|2=Exp-default=1250235324%2F2=1,; _chartbeat2=sq6k5rzuuoqiwvy6

Response

2.2. http://www.groupon.com/user_demographics/demographic_form_banner.html previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/user_demographics/demographic_form_banner.html

Issue detail

The following cookie was issued by the application and is scoped to a parent of the issuing domain:

_thepoint=c34d720c801b2b00e49f006c1240e874; domain=.groupon.com; path=/; expires=Wed, 02 Mar 2011 17:13:24 GMT; HttpOnly

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.

Request

GET /user_demographics/demographic_form_banner.html?addx=test@fastdial.net&_=1298999611622 HTTP/1.1
Host: www.groupon.com
Proxy-Connection: keep-alive
Referer: http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301
x-requested-with: XMLHttpRequest
content-type: application/x-www-form-urlencoded
accept: text/javascript, text/html, application/xml, text/xml, */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.107 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: b=2148c93a-394a-11e0-aca6-005056951763; visited=true; _chartbeat2=sq6k5rzuuoqiwvy6; subscriber_email=test%40fastdial.net; _tpaid=newsletter; adchemy_id=; _tpmed=email; division=san-jose; s=29108ae4-4427-11e0-ae71-005056952866; email=test%40fastdial.net; _thepoint=c34d720c801b2b00e49f006c1240e874; __utmz=44473723.1298999612.2.5.utmcsr=newsletter|utmccn=(not%20set)|utmcmd=email|utmcct=san-jose_feed; __utma=44473723.1103413385.1297805149.1297805149.1298999612.2; __utmc=44473723; __utmv=44473723.|2=Exp-default=1250235324%2F2=1,; __utmb=44473723.1.10.1298999612

Response

HTTP/1.1 200 OK
Server: nginx/0.7.65
Date: Tue, 01 Mar 2011 17:13:24 GMT
Content-Type: text/html; charset=utf-8
Set-Cookie: subscriber_email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:24 GMT
Set-Cookie: adchemy_id=; path=/
Set-Cookie: division=san-jose; path=/; expires=Fri, 01-Apr-2011 17:13:24 GMT
Set-Cookie: email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:24 GMT
Set-Cookie: mobile=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _thepoint=c34d720c801b2b00e49f006c1240e874; domain=.groupon.com; path=/; expires=Wed, 02 Mar 2011 17:13:24 GMT; HttpOnly
Status: 200
ETag: "7a503aa81cd310231b4f95be703b97d3"
X-Runtime: 38
Cache-Control: private, max-age=0, must-revalidate
Connection: close

<div class='clearfix' id='above_main'>
<div class='demographic_banner clearfix' id='demographic_collection_form'>
<form action="/user_demographics/update_with_optional_subscription" class="new_u
...[SNIP]...

3. Cross-domain Referer leakage previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/san-jose/deals/pure-barre-los-gatos-1

Issue detail

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

http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301

The response contains the following links to other domains:

http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js
http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.6/jquery-ui.min.js
http://ajax.microsoft.com/ajax/jquery.validate/1.7/jquery.validate.js
http://assets1.grouponcdn.com/assets/application.js?TejW351l
http://assets1.grouponcdn.com/assets/deal_page.js?bjmlvcjw
http://assets1.grouponcdn.com/assets/facebook.js?rpq--NbY
http://assets1.grouponcdn.com/favicon.ico?Jzth5gNo
http://assets1.grouponcdn.com/groupon.ico?Jzth5gNo
http://assets1.grouponcdn.com/images/groupon/icons/hourglass/hourglass002.gif?7cD-xrqw
http://assets1.grouponcdn.com/images/groupon/icons/icon_house.gif?rWAapTMb
http://assets1.grouponcdn.com/images/groupon/icons/small_price_tag.gif?-yiwnt5m
http://assets1.grouponcdn.com/images/groupon/icons/tipometer/check_mark.png?SxxwvrIa
http://assets1.grouponcdn.com/images/groupon/merchants/groupon-promise.png?axl8XglH
http://assets1.grouponcdn.com/images/groupon/overlays/btn/x-close-large.png?WcTqZeiv
http://assets1.grouponcdn.com/images/groupon/price_tag_view.png?AFizOWHs
http://assets1.grouponcdn.com/images/site_images/0616/9903/Pure-Barre4_Los-Gatos.jpg?BPAIUc4q
http://assets1.grouponcdn.com/images/site_images/0633/1101/San-Jose-Chamber-Orchestra2_grid_3.jpg?J-fAnUdp
http://assets1.grouponcdn.com/images/site_images/0633/1101/San-Jose-Chamber-Orchestra2_sidedeal.jpg?4vgl9c9M
http://assets1.grouponcdn.com/images/site_images/0634/5347/Poppy-Hills-Golf-Course-_San-Jose__grid_3.jpg?3ma1AvCV
http://assets1.grouponcdn.com/images/site_images/0634/5347/Poppy-Hills-Golf-Course-_San-Jose__sidedeal.jpg?PDspCgb9
http://assets1.grouponcdn.com/images/site_images/0637/2701/Cinequest2_grid_3.jpg?C8zL7Zgu
http://assets1.grouponcdn.com/images/site_images/0637/2701/Cinequest2_sidedeal.jpg?nIHr26-E
http://assets1.grouponcdn.com/images/site_images/0637/5868/Specialty-Sports-Colorado-Ski-and-Golf_-Breeze_Any-Mountain-The-Great-Outdoor-Store2_grid_3.jpg?Ej7prn5J
http://assets1.grouponcdn.com/images/site_images/0637/5868/Specialty-Sports-Colorado-Ski-and-Golf_-Breeze_Any-Mountain-The-Great-Outdoor-Store2_sidedeal.jpg?8nHrEKgi
http://assets1.grouponcdn.com/javascripts/app/deals/show.js?hPqXFwmo
http://assets1.grouponcdn.com/javascripts/common/demographic_form_banner.js?oflEbeJc
http://assets1.grouponcdn.com/javascripts/common/tooltip.js?YQelxRZ9
http://assets1.grouponcdn.com/stylesheets/app/deals/show.css?mWGaSnRG
http://assets1.grouponcdn.com/stylesheets/base.css?-r1wfD6Q
http://feeds.feedburner.com/grouponsan-jose
http://gr.pn/eXYRSA
http://groupon.ca/
http://latimesblogs.latimes.com/holiday-gift-guide/2009/11/pure-barre-offers-discounted-packages-for-the-holidays.html
http://maps.google.com/maps/api/staticmap?size=186x186&sensor=false&markers=color:red|size:mid|37.223461,-121.981903
http://maps.google.com/maps/api/staticmap?size=280x280&sensor=false&markers=color:red|size:mid|37.223461,-121.981903
http://maps.google.com/maps?f=d&daddr=50+University+Ave.+Suite+B-101+Los+Gatos+California+95030
http://platform.twitter.com/widgets.js
http://purebarre.com/p-people.html
http://twitter.com/share?url=http%3A%2F%2Fwww.groupon.com%2Fgroupon_says%2Fgroupon-says-33063426&text=Is%20showing%20up%20for%20a%20party%20a%20day%20early%20considered%20...fashionably%20early...%3F%20-%20
http://twitter.com/share?url=http%3A%2F%2Fwww.groupon.com%2Fsan-jose%2Fdeals%2Fpure-barre-los-gatos-1%3Futm_campaign%3DVisitorReferral%26amp%3Butm_medium%3Dtwitter%26amp%3Butm_source%3Danonymous&text=%2440%20for%20Four%20Body-Toning%2C%20Fat-Burning%20Workout%20Classes%20at%20Pure%20Barre%20%20-%20%2488%20Value...
http://www.atlaspost.com/buy
http://www.beeconomic.com.ph/
http://www.cafepress.com/groupon
http://www.citydeal.fi/
http://www.citydeal.ie/
http://www.citydeal.it/
http://www.clandescuento.com/countries/s/chile
http://www.clubeurbano.com.br/
http://www.facebook.com/grouponsanjose
http://www.flickr.com/photos/grouponcorporate/sets
http://www.groupon.at/
http://www.groupon.be/
http://www.groupon.ch/
http://www.groupon.de/
http://www.groupon.es/
http://www.groupon.fr/
http://www.groupon.gr/
http://www.groupon.jp/
http://www.groupon.nl/
http://www.groupon.pl/
http://www.groupon.se/
http://www.groupon.sg/
http://www.grouponworks.com/
http://www.la.com/ci_12185175?source=rss
http://www.la2day.com/health_beauty/pure_barre_sets_the_bar_for_results_oriented_workouts
http://www.liveoffgroupon.com/
http://www.meetup.com/groupon
http://www.mycitydeal.dk/
http://www.mycitydeal.no/
http://www.purebarre.com/CA-losgatos/index.html
http://www.sehirfirsati.com/
http://www.twitter.com/grouponsanjose
http://www.ubuyibuy.com/
http://www.yelp.com/biz/pure-barre-los-gatos-los-gatos
https://clients.mindbodyonline.com/asp/home.asp?studioid=8734

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

Response

HTTP/1.1 200 OK
Server: nginx/0.7.65
Date: Tue, 01 Mar 2011 17:13:00 GMT
Content-Type: text/html; charset=utf-8
Set-Cookie: subscriber_email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:00 GMT
Set-Cookie: utm_term=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpmed=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: utm_campaign=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: b=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: external_uid=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpref=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpoid=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpref2=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpuid=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: utm_source=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: utm_content=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: utm_medium=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpcid=; domain=.groupon.com; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: _tpaid=newsletter; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
Set-Cookie: adchemy_id=; path=/
Set-Cookie: _tpmed=email; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
Set-Cookie: division=san-jose; path=/; expires=Fri, 01-Apr-2011 17:13:00 GMT
Set-Cookie: s=29108ae4-4427-11e0-ae71-005056952866; path=/
Set-Cookie: email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:00 GMT
Set-Cookie: mobile=; path=/; expires=Thu, 01-Jan-1970 00:00:00 GMT
Set-Cookie: email=test%40fastdial.net; path=/; expires=Fri, 01-Apr-2011 17:13:00 GMT
Set-Cookie: _thepoint=c34d720c801b2b00e49f006c1240e874; domain=.groupon.com; path=/; expires=Wed, 02 Mar 2011 17:13:00 GMT; HttpOnly
Status: 200
ETag: "2c59701df41e4f9c877f397fdffda210"
X-S-COOKIE: 29108ae4-4427-11e0-ae71-005056952866
X-Runtime: 161
Cache-Control: private, max-age=0, must-revalidate
Connection: close

<!DOCTYPE html>


<script src="http://assets1.grouponcdn.com/javascripts/common/tooltip.js?YQelxRZ9" type="text/javascript"></script>
<script src="http://assets1.grouponcdn.com/assets/deal_page.js?bjmlvcjw" type="text/javascript"></script>
<script src="http://platform.twitter.com/widgets.js" type="text/javascript"></script>
<script src="http://assets1.grouponcdn.com/assets/facebook.js?rpq--NbY" type="text/javascript"></script>
...[SNIP]...
</script>
<script src="http://assets1.grouponcdn.com/javascripts/app/deals/show.js?hPqXFwmo" type="text/javascript"></script>
<script src="http://assets1.grouponcdn.com/javascripts/common/demographic_form_banner.js?oflEbeJc" type="text/javascript"></script>
...[SNIP]...

4. Cross-domain script include previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/san-jose/deals/pure-barre-los-gatos-1

Issue detail

The response dynamically includes the following scripts from other domains:

http://ajax.googleapis.com/ajax/libs/jquery/1.5.0/jquery.min.js
http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.6/jquery-ui.min.js
http://ajax.microsoft.com/ajax/jquery.validate/1.7/jquery.validate.js
http://assets1.grouponcdn.com/assets/application.js?TejW351l
http://assets1.grouponcdn.com/assets/deal_page.js?bjmlvcjw
http://assets1.grouponcdn.com/assets/facebook.js?rpq--NbY
http://assets1.grouponcdn.com/javascripts/app/deals/show.js?hPqXFwmo
http://assets1.grouponcdn.com/javascripts/common/demographic_form_banner.js?oflEbeJc
http://assets1.grouponcdn.com/javascripts/common/tooltip.js?YQelxRZ9
http://platform.twitter.com/widgets.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

Response

5. Cookie without HttpOnly flag set previous next
There are 2 instances of this issue:

/san-jose/deals/pure-barre-los-gatos-1
/user_demographics/demographic_form_banner.html

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.

5.1. http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1 previous next

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/san-jose/deals/pure-barre-los-gatos-1

Issue detail

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

subscriber_email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:00 GMT
_tpaid=newsletter; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
_tpmed=email; domain=.groupon.com; path=/; expires=Tue, 08-Mar-2011 17:13:00 GMT
division=san-jose; path=/; expires=Fri, 01-Apr-2011 17:13:00 GMT
s=29108ae4-4427-11e0-ae71-005056952866; path=/
email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:00 GMT
email=test%40fastdial.net; path=/; expires=Fri, 01-Apr-2011 17:13:00 GMT

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.

Request

Response

5.2. http://www.groupon.com/user_demographics/demographic_form_banner.html previous

Summary

Severity:	Information
Confidence:	Certain
Host:	http://www.groupon.com
Path:	/user_demographics/demographic_form_banner.html

Issue detail

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

subscriber_email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:24 GMT
division=san-jose; path=/; expires=Fri, 01-Apr-2011 17:13:24 GMT
email=test%40fastdial.net; path=/; expires=Mon, 01-Mar-2021 17:13:24 GMT

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.

Request

GET /user_demographics/demographic_form_banner.html?addx=test@fastdial.net&_=1298999611622 HTTP/1.1
Host: www.groupon.com
Proxy-Connection: keep-alive
Referer: http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301
x-requested-with: XMLHttpRequest
content-type: application/x-www-form-urlencoded
accept: text/javascript, text/html, application/xml, text/xml, */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.107 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: b=2148c93a-394a-11e0-aca6-005056951763; visited=true; _chartbeat2=sq6k5rzuuoqiwvy6; subscriber_email=test%40fastdial.net; _tpaid=newsletter; adchemy_id=; _tpmed=email; division=san-jose; s=29108ae4-4427-11e0-ae71-005056952866; email=test%40fastdial.net; _thepoint=c34d720c801b2b00e49f006c1240e874; __utmz=44473723.1298999612.2.5.utmcsr=newsletter|utmccn=(not%20set)|utmcmd=email|utmcct=san-jose_feed; __utma=44473723.1103413385.1297805149.1297805149.1298999612.2; __utmc=44473723; __utmv=44473723.|2=Exp-default=1250235324%2F2=1,; __utmb=44473723.1.10.1298999612

Response

6. Content type incorrectly stated previous

Summary

Severity:	Information
Confidence:	Firm
Host:	http://www.groupon.com
Path:	/deals/pure-barre-los-gatos-1/deal_status.json

Issue detail

The response contains the following Content-type statement:

Content-Type: application/json; charset=utf-8

The response states that it contains JSON. However, it actually appears to contain HTML.

Issue background

If a web response specifies an incorrect content type, then browsers may process the response in unexpected ways. If the specified content type is a renderable text-based format, then the browser will usually attempt to parse and render the response in that format. If the specified type is an image format, then the browser will usually detect the anomaly and will analyse the actual content and attempt to determine its MIME type. Either case can lead to unexpected results, and if the content contains any user-controllable data may lead to cross-site scripting or other client-side vulnerabilities.

In most cases, the presence of an incorrect content type statement does not constitute a security flaw, particularly if the response contains static content. You should review the contents of the response and the context in which it appears to determine whether any vulnerability exists.

Issue remediation

For every response containing a message body, the application should include a single Content-type header which correctly and unambiguously states the MIME type of the content in the response body.

Request

GET /deals/pure-barre-los-gatos-1/deal_status.json HTTP/1.1
Host: www.groupon.com
Proxy-Connection: keep-alive
Referer: http://www.groupon.com/san-jose/deals/pure-barre-los-gatos-1?utm_medium=email&utm_source=newsletter&c=title&addx=test@fastdial.net&utm_content=san-jose_feed&user=test@fastdial.net&d=deal&divison=san-jose&s=more_deals_for_you&p=0&date=20110301
x-requested-with: XMLHttpRequest
content-type: application/x-www-form-urlencoded
accept: text/javascript, text/html, application/xml, text/xml, */*
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.107 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: b=2148c93a-394a-11e0-aca6-005056951763; visited=true; _tpaid=newsletter; _tpmed=email; s=29108ae4-4427-11e0-ae71-005056952866; __utmz=44473723.1298999612.2.5.utmcsr=newsletter|utmccn=(not%20set)|utmcmd=email|utmcct=san-jose_feed; __utma=44473723.1103413385.1297805149.1297805149.1298999612.2; __utmc=44473723; __utmv=44473723.|2=Exp-default=1250235324%2F2=1,; __utmb=44473723.9.2.1298999613665; subscriber_email=test%40fastdial.net; adchemy_id=; division=san-jose; email=test%40fastdial.net; _thepoint=c34d720c801b2b00e49f006c1240e874; _chartbeat2=sq6k5rzuuoqiwvy6

Response

HTTP/1.1 200 OK
Server: nginx/0.7.65
Content-Type: application/json; charset=utf-8
Status: 200
ETag: "229722a1959db23513932e874f89324c"
X-Runtime: 15
Cache-Control: max-age=60, public
Age: 36
Date: Tue, 01 Mar 2011 17:18:23 GMT
Expires: Tue, 01 Mar 2011 17:18:47 GMT
Connection: keep-alive
Content-Length: 769

{"deal_day":3,"deal_hour":7,"deal_min":59,"number_sold_container":"\n<table class='status'>\n <tr class=\"sum\"><td class=\"left\"><span class=\"number\">196</span></td><td class=\"right\"> bought</t
...[SNIP]...

Report generated by XSS.CX Research Blog at Tue Mar 01 11:32:41 CST 2011.